SMALL REEF AQUARIUM BASICS 
 
Introduction


The interest in Reef Aquariums has recently grown in
popularity so rapidly, that everyone, including Pet Store Owners
and personnel, have a hard time keeping up with all the
developments that are occuring. New filtration methods, and new
equipment, appear in the magazines, and in advertising, every
month.

Newer  methods for keeping such aquariums, including very hi-tech 
instrumentation, are being advocated all the time. Sophisticated 
testing is recommended as well. In short, a completely different 
approach than the one Hobbyists and Stores have been accustomed 
to, leading to a lot of confusion and misunderstandings, 
especially since some of the recommendations have not been tested 
over long periods of time yet, and may even conflict.

Although books such as "The Marine Fish and Invert Reef 
Aquarium", and "Advanced Reef Keeping Made Simple" have obviously 
helped a great deal, both are concerned with larger systems. 
Tanks in the 100 to 150 gallon range, a size that not many 
Hobbyists keep and that requires more sophistication, and the 
related expenses, because of the greater amount of animal life 
that is kept in such aquariums.

Of course, the methods advocated there, can be applied to smaller 
aquariums as well, but increase the budget required to get into 
Reef Keeping quite a bit.

Many Store Owners, and many Hobbyists, have suggested that I 
write a book geared more specifically to the Reef Keeper who 
wishes to maintain a small system successfully without having to 
spend thousands of dollars. Very instrumental in convincing me to 
undertake this project was Roger Paro, of Kenlin Pet Supplies, in 
Mahwah, New Jersey. This manuscript is, therefore, the product of 
all the suggestions received, and a little arm twisting from 
some.

The book is shorter than my other ones, mainly because interested 
readers can refer to both of them for a more detailed look at 
some of the subjects covered here. Additionally, some of the 
equipment discussed in the other books is not used in the set-up 
that I would like to suggest for the smaller aquarium, the one 
discussed here.

General aquarium keeping is not covered in this book. You should 
refer to one of the many other books available for more details 
on, e.g. heating, biological filtration, and why and how it takes 
place, stands, tanks, fish, other animals, background 
information, etc...
 
One such book that is strongly recommended is Martin A. Moe Jr.'s 
" The Marine Aquarium Reference - Systems and Invertebrates" 
1989, 510 pp, Green Turtle Publications. It contains a wealth of 
information and techniques that you may want to consider when 
setting up your new Reef Tank, or when making modifications to an 
existing aquarium. It is brand new and incorporates very 
up-to-date information, drawing on the latest technology 
available, and very recent texts, articles and books.

Martin Moe's contributions to the Hobby already stood out with 
his first book, Marine Aquarium Handbook, Beginner to Breeder 
this one tops it. Every serious Hobbyist should get a copy of it. 
It is available from stores nationwide.

Do not overlook the many books published by T.F.H. Publications 
either, they are, after all, the largest publishers of Aquarium 
literature in the world, and have books on many subjects of 
interest to the Reef Keeping Hobbyist. Your local Pet Store will 
usually have a wide assortment of their books.

What we are trying to achieve in this one, is setting up a Reef 
Tank on a budget! You may still have to spend more money than 
what you would lay out for a regular fish tank, but it certainly 
will not be a budget that resembles anything like the tanks 
described in both my other books, where most functions are auto- 
mated; or where I describe how you can introduce such   
automation, and what your options are.

No tank can be set up for two or three hundred dollars, but by 
following the directions in this guide you should be able to 
considerably reduce the cost of what you thought installing such 
a tank would necessitate. The cost of the aquarium and the stand 
are not part of what we will be reviewing.  You may have both 
already, or you may want to shop around for a special. Pet Stores 
have them all the time. Alternatively look in your local bargain 
newspaper. Fish tanks are advertised in such newspapers every 
week, and at excellent prices. You may even find some of the 
equipment you will need as well.

Because Reef Keeping is complex, much more so than just plain 
fish-only tanks, the selection of the items that you will be 
using is important. Buy products that will last you for a long
time. Avoid the "store-them-in-the-garage-or-attic and replace- 
them-with-something-else syndrome" so characteristic of what a 
lot of us have been doing in the past.

By buying the right product, of the right quality, you will buy 
only once. Let me illustrate this, for example, if you need an 
overflow surface-skimming syphon, and 3 are offered for sale, 
don't buy the cheapest one. Unless of course that happens to be 
the one that you need for your tank.

First determine what you need, then select what to buy. If you 
are looking at running several hundred gallons of water per hour, 
a syphon with half inch connections will not do the job, even 
though it may be the cheapest. All that will happen is that after 
a few weeks you will get tired of messing around with it, having 
determined that it doesn't really do the job, and end up buying a 
more expensive one anyway. As a result you end up spending more 
money than if you had bought the right one to begin with.

Determining what your exact needs are is half the battle. Once 
you know what you need, you can start looking around for the 
product that meets the specifications you have found to be 
necessary. That product will not become obsolete in a couple
of weeks or months, because it will be the right one for the job.

Another example is the redox potential meter. A meter alone will 
only tell you what the redox is. Soon you may get the urge to 
control it. A meter cannot do that. You will then want, and need, 
a redox potential controller. This is a different piece of 
equipment, that you will then need to buy, and it will obsolete 
the meter. The money spent on the meter will have been wasted. 
Think before buying and decide what it really is that you will 
want to do. Of course, in a small system you may not want to
automate, and then a meter will do fine.

Ask questions about the equipment. For instance, in the case of 
controllers, either for pH or redox potential, many less 
expensive models are so-called "panel mount" types, requiring 
hard wiring and having no full external cover.

What you are probably looking for is a so-called "bench top" 
model, one in which you can just plug in the device (e.g. ozone, 
chemical metering pump, peristaltic pump) that you are trying to 
control, without any wiring whatsoever.

Keep these remarks in mind every time you need to acquire some 
piece of equipment or instrument. They will save you a lot of 
money in the long run.

Reef Keeping is fascinating and it can be great fun, but you must 
meet certain minimum requirements in water quality, or your tank 
just will not look good. What these parameters are, and how to 
attain them on a smaller budget is the purpose of this book.

Setting up a Reef Tank will still cost a fair amount of money, 
but using the methods described here, a lot less than if you went 
with a full-fledged automated system such as the ones described 
in my other two books, or often referred to in Marine Reef, the 
newsletter of which I have the pleasure of being the Editor. Such 
systems are of course much more self-sufficient, but obviously at 
a cost.

We hope that the recommendations made in this book will help, and 
welcome suggestions for inclusion in future editions, and 
reprints. If we have overlooked something, if a particular method 
has worked for you, let us know about it.

Sharing knowledge is what it's all about.

As a final note, don't expect any miracles, successful aquarium 
keeping is a combination of a fair amount of knowledge, common 
sense practices, and the right equipment. Good luck in your 
endeavors.

Albert J. Thiel
Trumbull, Connecticut


A special note of thanks to Guido Hueckstedt,
whose contributions to the Hobby, and
research, are so often overlooked.


We also wish to acknowledge :

Martin A. Moe

and most of all

Sarah R. Thiel
for her patience and understanding
during the writing of this manuscript.
Her support was invaluable to me. 

FILTRATION

  General Remarks

All, or almost all, successful Reef Systems that I have ever seen 
have one thing in common: they segregate the various modes of 
filtration required to maintain optimum water quality levels and 
chemistry. We should try to learn from that empyric evidence, and 
duplicate the methods used by such successful Reef Keeping 
Hobbyists.

The various segregated methods of filtration that I am referring 
to here, include the following, most of which you are familiar 
with to some extent:

  Mechanical filtration, or fine and micron:sub-micron 
filtration, to remove so-called detritus or particulate matter
from the water,

  Biological filtration, to break down ammonia, nitrite, and 
convert the latter to nitrate,

  Chemical filtration to remove pollutants that the 2 methods 
mentioned above do not,

  Foam fractionation, to remove e.g. protein before it breaks   
down further and pollutes the water,

  Pressure filters - contact chambers for oxygen and ozone, this 
includes, for example, oxygen reactors, ozone reactors and such,

  Miscellaneous methods, e.g. denitrators, specialized resins, 
tangential flow filters, biomesh filters, aerobic nitrate 
filters, etc. 

Some of these will, for obvious reasons, not be used on the small 
Reef System that we are dealing with in this book: they are meant 
to be used on more automated systems, and several of them involve 
quite a considerable expense. Pressurized contact chambers such 
as oxygen reactors, for instance, can cost around $250.00, and 
tangential flow filters quite a bit more.

Filtration is of course the one important aspect of the total 
system that determines whether your Reef will be successful or 
not. It is, indeed, through proper filtration that the water is 
cleansed of impurities and unwanted compounds and chemicals. 
This, then, ensures a proper living environment for the fish and
invertebrates kept in the tank. Because you add fish, corals and
invertebrates, the water quality deteriorates; there is no way
around it. A real minimum amount of filtration, that you cannot 
do without is, as a result, necessary for you to be a successful
reef Hobbyist, as it will remove those unwanted noxious elements.

Everything ultimately boils down to the quality of the water. The 
better that quality, the better your Reef Aquarium will look. The 
worse the water chemistry, the worse the tank will look, and the 
more life forms will die, which in turn leads to even more 
problems. Polluted water is the nemesis of every Aquarist.

The accumulation of breakdown products of organic and non-organic 
nature will eventually drop the quality of the water so much, 
that the tank turns into an environment not suitable for animals. 
Keep it in mind! And if you do not take care of your system this 
can happen in a matter of days, sometimes even hours. Fish and 
invertebrates take the abuse for a while, and then suddenly 
things will deteriorate very quickly, often to the hobbyist's 
surprise, as only a few hours earlier everything "seemed" to be 
fine.

Good water chemistry does not happen by chance, it can be 
attained only in 2 major ways: continuous water changes (the
so-called completely open system), or proper and well maintained
filtration of at least four kinds, the ones listed higher up,
mechanical, biological, chemical and foam fractionation.
Fortunately for us, three of these four can nowadays be combined
in one unit: the trickle filter. Not all trickle filters on the
market, however, offer this feature. If you are in the market for
one, check whether the filter that you are looking to acquire
incorporates the required filtration steps on one hand, and does
so in a segregated fashion on the other, allowing you to control
and service mechanical, biological and chemical filtration
separately, and in their own right without affecting anything
else.

Only when such is possible, will you be able to work on your
filters to service and maintain them, without affecting what is
happening to the others. Mechanical filters need very regular
cleaning, chemical filters need to be changed from time to time
and rinsed to remove detritus, whereas biological filters should
always be left alone.

Bacteria in the biological filters (chamber) should not be
disturbed by the cleaning process, or by moving the material on
which they grow, around or in and out of the filters. Doing so
always results in a loss of bacteria, and a considerable
reduction in the efficiency of the filters. The latter may
result in an increase in ammonia and nitrite and stress to tank
life forms. Stress often brings about disease. Usually parasitic
disease. The latter is very hard to treat in Reef Tanks, as no
copper or similar compounds can be used, because of the
invertebrates in the tank. Both stress and disease can rapidly
lead to massive outbreaks of parasitic infestations because one
infected fish, acting as a host, brings about a rapid
multiplication of parasites, which then attack other fish. A real
vicious circle which is then very hard to control.

Filtration, and how its various components are set up is,
therefore, very important for the long time appearance and
health of the aquarium. The selection of the components of the
filtration system must, as a result, be carefully planned and
thought out in advance.

Many Hobbyists pay little or no attention to mechanical
filtration. That is a considerable mistake. Mechanical filtration
is, indeed, an important part of maintaining adequate water
chemistry parameters. Biological filtration does get a lot of
attention, perhaps too much sometimes. Chemical filtration is
going through a growth stage, and more and more Hobbyists are
starting to realize its importance, which is an excellent trend,
of course.

In the subsequent chapters we will take a more in depth look at 
each of these strongly recommended forms of water filtration, and 
suggest how they should be incorportated in a small reef 
aquarium.


MECHANICAL FILTRATION

        Mechanical filtration is nothing more than removing many
types of unwanted particulate matter from the system, by first
trapping it in a dedicated location (or several such locations),
and then cleaning those locations to remove the matter entirely
from the tank and filters.

        Merely moving it from inside the tank, where you can see
it floating around in the water, to the filters, does not improve
the water quality at all. The only thing such achieves, is
removing it from your sight, but not from the water. Leaving
particulate matter trapped in the mechanical filters for too long
does, in fact,  more damage than good, as once the trapped matter
is concentrated in a small area, it can quickly deplete large
amounts of oxygen from the water. This material may then start
decaying in an anaerobic (anoxic - oxygen poor or oxygen
depleted) manner. This can quickly add many compounds that are
totally undesirable, and dangerous, to the water . These
compounds result from break-down by-products. The better known
one that you are probably familiar with is hydrogen sulfide, but
there are many other such breakdown products that you do not want
in the tank's water. Even small amounts of hydrogen sulfide lower
the water quality enough, for your lifeforms not to look at their
best.

        Even if the decay that takes place does not remove all
the oxygen (which it will in the extreme case), it can still
remove considerable amounts, and lower dissolved oxygen to
dangerous levels for all animal life you keep in the tank. They
may not die, they will more than likely not, but they will just
not look as good as they would, if the water quality were better.

        It is all a matter of degree; the difference between a
vibrant looking aquarium, and one that looks all right to you,
but does not draw any oh's and ah's from your friends or
visitors.

        Mechanical filtration is, therefore, a two-step process :
first you trap the dirt, detritus, floculate, particulate, (all
names for what we are trying to remove) in a specially designed
area by means of a screen, mesh, cartridge, floss, or other form
of filter, and secondly you clean those filters regularly to
remove that matter entirely from the system (the mass of water in
your tank and filters). Doing so prevents whatever you trapped in
the filters from breaking down, causing problems for you by
lowering the water quality (usually evidenced by lower dissolved
oxygen levels in the water). At the same time, because you
prevented the decay, you also prevented the addition of other
compounds that result from such decay, to the tank's water.

        Some of these breakdown compounds may even be more toxic
than the particulate matter that you trapped to begin with,
obviating the need to clean your mechanical filters on a very
regular basis. Once a week, or even more frequently, is strongly
recommended.

        Anything that can trap dirt acts as a mechanical filter,
even materials in the tank and filters that you may not think
about, e.g. the material used inside the trickle filter's
biological filtration area (I am referring to material that is
dense, close-meshed, or that packs and restricts the flow of the
water, e.g. gravel).

        Keep this in mind because, often, areas such as those
never get cleaned, or they are cleaned much too infrequently.
Examples are calcite layers in the bottom of filters, undergravel
filters that are in dis-use or are used on a reduced flow rate,
etc...

        Mechanical filters come in many forms. They could be
canisters filled with material such as EfiMech from Eheim, or
Biomech from Kordon, filter floss, pads, blue-white bonded pads,
bags; or they can be specially designed containers with pleated
cartridges or bags, and many others still.

        All work efficiently and will trap lots of detritus. The
finer the material, the more it will remove, especially after it
has accumulated some dirt already. As the spaces where the water
can flow through get smaller, get restricted, finer and finer
particles will be trapped.  This will slow the flow of water
through the material down as well, which is yet another reason
why you should clean all such filters regularly.

        Here is a short overview of the most common types of
mechanical filtration methods used, and available to the
Hobbyist. You should use at least one of them, but you may want
to combine several in your system, for optimum efficiency.

   CANISTERS (traditional) :

        You probably know many of these filters under names such
as Eheim, PEP, Lifeguard, Magnum, Fluval, Atlantis, Tech, and
assume that they all fall in the same category. That is not the
case. Some are meant to be strictly mechanical filters, others
can be adapted to perform several distinct functions: mechanical,
chemical, biological, even heating, or a combination of several
of those. The latter is what we would like to strongly
discourage. Segregate, don't combine. Keep all forms of
filtration separate from each other.
 
        We must also differentiate between the traditional
canister filters such as the Eheim, Fluval and Magnum types, and
the others mentioned. The former can be loaded, or filled, with
varying types of products, each one of which is meant to perform
a different function. The latter are more of a pressure type
filter, excellent at mechanical filtration.
        
        In fish-only tanks that was certainly a very
appropriate way of using these filters; in Reef tanks, we would
like to discourage you from doing so (combining several
filtration methods).

        Remember, we are trying to keep all forms of filtration
separate from each other, and since we will be using a trickle
filter (see biological filtration), if you use a traditional
canister, you should use it as either a mechanical or a chemical
filter, not a combination.

        Let's review how to use them as mechanical filters. Refer
to the last section in this chapter to check up on chemical
filtration canisters.
        Canister filters have one great advantage : they can
easily be opened and serviced. That is a boon ! The easier it is
to clean a filter, the more often the Hobbyist is likely to do
so. And cleaning the inside of mechanical filters often is a
requirement, not an option, as we have already seen.

        Fill your canister with any material that is available in
your local area pet store, and that is meant to be used in a fine
filter. Pack it in firmly, but not too tightly, lest you will
restrict the water flow too much. Canister filters can move a
fair amount of water, but their pumps do not usually take a lot
of back pressure. Switch the canister on, and you will be
mechanically filtering the water on a continuous basis. You can
take water from the bottom of the trickle filter (sump), and
return it to the same area, or you can return it to the tank
directly, or to the top of the trickle filter. All three are
acceptable. In-line mechanical filters are discussed later.

        Many Hobbyists use filter floss, some use ceramic tubes
such as EfiMech from Eheim (stands for efficient mechanical
filtration), kordon's equivalent : BioMech, pads such as
blue-white bonded ones, coarse gravel, DLS or copy-cats of the
original, foam sponges (beware though that most foam is
bio-degradable, and if it is not, it may have been treated with
compounds you do not want in your tank), natural sponges (my
favorite), crushed coral, small coral rubble, Efigross (grob) a
fine mesh of green plastic marketed by Eheim, layers of untreated
viscose, and a host of other materials (hobbyists are very
resourceful in this respect).

        Clean the filter(s) at least once a week, more often is
even better. Do not worry about bacterial loss, mechanical
filters are not meant to act biologically. That is not their
purpose. In fact, more often than not, the bacteria that grow in
mechanical filters that are not regularly cleaned, do more harm
than good, and some even suggest (de Graaf, 1976) that they may
be the cause of wipe-outs, in some cases (Shigella type
bacteria).

        Cleaning the canister, cum mechanical filters, involves
removing all the material that you placed inside, and rinsing it
thoroughly in fresh water before placing it back in the canister.
Sometimes it even pays to use new material, e.g. in the case of
filter floss. Some materials need to be scrubbed, others
bleached. In the latter case make sure you rinse them several
times to remove all bleach leftovers. Do not, if you can avoid
it, use dechlorinators. I do not care for their use in Reef
tanks.

        In order to make this process as easy as possible, it is
suggested that you use quick disconnect shut-off valves, on
either side of the canister filter. This will allow you to take
it out of service without having to worry about water spillage,
except for the very little water that is between the canister and
the quick disconnect valves.

        Eheim, Fluval and Marineland make such valves, and there
may be others. American made ones are as good as the imports, so
my suggestion is that you save yourself the extra cost, as
imported ones are usually more expensive, and not necessarily
better.
        
        The size of the canister should be in direct
relation to the size of the system that you have. In most cases a
Fluval 303, or perhaps a 403 for 55 gallon aquariums will be
fine. This may be larger than what you expected, but you will
benefit from the extra mechanical filtration ability that you
will have. There are of course other brands; get the larger
models if you can afford them, they will do a better job for you,
as they hold more filtering material.

        Eheim, probably the inventor of the canister filter, has
recently introduced its 2200 series, very similar to the previous
2000 series, but with slightly more flow, and a normalized shaft.
These top-of-the-line canisters are really good value for your
money and hold up for years and years. I personally use Eheim
2217Us whenever I need canister filters.

        Filter floss is, in my opinion, just about as good as
anything else you can find on the market. It is easy to use,
relatively inexpensive, and can therefore be replaced each time
you clean the filters. Buy it in bulk.

        Make a habit of cleaning your canister(s) at least once a
week. Your system will greatly benefit from it. That is my
experience anyway. And if, as suggested, you use quick disconnect
valves, cleaning and changing will not be a chore at all.

         Remember, the easier it is to clean your mechanical
filter, the more often your are likely to do so, for the benefit
of your system. I have said so for a very long time, and must
remind you, that only when you first set up your tank, can you
meaningfully influence this. Install all mechanical filters in a
way that will let you reach them easily.

   CANISTER FILTERS (special)

        Special canisters can be acquired to mechanically filter
the water. Two examples are the PEP and Lifeguard Systems. These
units usually require some piping, unlike the traditional
canisters which the Hobbyist can just plug them in and run. Their
installation is, however, not complicated, and if you already
have them, by all means use them.

        Most of these filters (there are others besides the two
mentioned) use some form of pleated bag, or pleated device, to
increase the amount of surface area through which the water can
flow and be filtered. The more surface area, the better the
filtration, of course.

        The bags can be used as such, or special powders (often
diatomaceous earth) can be added to the filter, to step the
filtration up to very fine levels, in this case referred to a
micronic.
 
        Cleaning is a little more involved, as these bags usually
need to be bleached to remove the accumulated detritus. This
takes more time and requires that you make sure all the bleach is
removed, before putting the bags, or other material, back in the
canisters. It is, actually, a good idea to have an extra bag or
pleated cartridge around. Especially so if your local pet shop
does not normally carry them.

        Because of the way they need to be cleaned, the pleated
bags or cartridges will wear out. Make sure that whomever you buy
such a unit from, if you decide to include this in your filtering
system, will also be able to supply you with replacements. Some
dealers don't, or you may have to special order them.

        Although this type of filtration can be very efficient,
it is, in my opinion, not a necessary expense on the smaller Reef
Tank. However, if you have such a filter already, it is
recommended that you use it anyway. They are indeed very
efficient at removing even very fine particulate matter.
        
        Some units come with pressure gauges. This allows
you to determine when it is necessary to clean the cartridge
(pleated bag or other device) based on what the manufacturer
suggests. Indeed, increased levels of pressure inside the
canister are an indication that it is plugged, and needs
cleaning. Retro-fitting such pressure gauges is also possible.

        If you plan to use one of these units, make sure that the
pump that you will be using can handle the back pressure brought
about by these filters. Small pumps will not do the job. Again,
most manufacturers suggest which pump you should use.

        Because canister filters are very versatile, some brands
are offered in various configurations, e.g. heater modules,
chemical modules, and of course, mechanical modules. Lifeguard
and PEP are two examples.

        Unless you already have one of them, we recommend an
alternative way of fine filtration; less expensive than acquiring
such units. Use either a canister, or check the section on
trickle filters to see how fine filtering can be incorporated in
the trickle filter itself. In fact, ideally, this option should
be provided in the trickle filter you should get, either as an
easy add-on option, or already built-in.

        Special canisters, such as the ones described, come in
various sizes, and if you plan on getting one, match the size up
with what is recommended for your tank. Better still, buy one
size larger. It can't hurt the system, and if you up-grade to a
larger tank, you will probably already have the right size
canister, and save yourself the extra expense of having to buy a
new one. You may not be thinking about a larger tank right now,
but believe me you will at some point. Most Hobbyists do.

        Servicing will require that you shut your pump down, as
these filters are usually piped in-line with the main water flow
back to the tank. In fact, some tanks' filtration consists only
of a series of these special canisters. Such may be efficient,
but in a Reef set-up we do not recommend that you use such
filtration as the only means of maintaining water quality. They
can, as we have seen, be used as add-ons to the trickle filter,
especially for mechanical and chemical filtration.

        Shut-off valves should be placed on either side of these
units, to allow for quick and easy opening and servicing. True
union ball valves are probably the easiest type to use.
Quick-disconnect shut-off valves are another possibility, and for
most Hobbyists a less expensive way to go.

        Piping in a by-pass line may be a worthwhile option, as
it will allow you to service the filter without having to stop
your system. To check how this is done, look at the drawing, a
few pages ahead, in the section on molecular absorption filters
and micron filters.

        These type of special canister filters are often used in
swimming pool and similar installations (e.g. spas). When
shopping around for one, check your local pool places too. You
may be able to get yourself a bargain. If you need fittings and
plastic pipe, check the hardware stores, the do-it-yourself
stores, and best of all, the local plumbing supply places. If you
run out of options, U.S. Plastics, also called Industrial
Plastics, in Lima, Ohio, sells by mail and has excellent prices.

   DIATOMACEOUS EARTH FILTERS
        
        Diatomaceous earth, the skeletons of diatoms, allows
extremely fine filtering, usually down to 1 micron, a level at
which many parasites are trapped as well.

        This is very efficient filtering, but should, in my
opinion, not be used too regularly on a Reef Tank, as it will
filter out all of the free floating lifeforms that many filter
feeders in your tank require for survival. Tanks always contain
filter feeders, and depriving them of the food they require is
not a sensible way to run such an aquarium.

        If you use a Vortex Diatom, a Marineland, or a System 1
diatom filter, do so infrequently, and not for many many hours
in a row. Use them to clean the water after you stir up the
bottom, to remove particulate matter that is now floating
around, and then clean the filter and put it away for a while.
Regular use is, in my opinion not recommended. Of course, in
fish-only tanks they can be run continuously.

        Suggestions have also been made that the use of
diatomaceous earth may add silicates to the water (Thiel 1986,
1988).

        That is undesirable insomuch as it may result in the
appearance of live diatoms, which will make the tank look really
unsightly. To demonstrate this fact, run water through a
diatomaceous earth filter for a few hours, and test for silicate
both before and after. You will be up for some real surprises.

        Some of these filters can be used with powdered  
activated carbon as well. This is something to consider doing on
an infrequent basis : once every 2 weeks, to once a month
perhaps, to clean up the water chemically as well. Never use the
diatom powder more than once. Clean the filter after each use and
throw the powder away. If you let it sit in the filter, it will
cake up, and anaerobic bacteria will appear within hours. When
you then switch the unit back on, all the noxious compounds in
the filter will enter your tank. A most dangerous situation that
can lead to many problems, including massive die-offs !

        Should you get such a filter for your Small Reef ? My own
answer is no. The drawbacks are the filtering out of fine matter
that filter filters need, and the possibility that silicates are
added to the water and may give rise to live diatoms (for example
Navicula, Berkeleya). If you happen to have one, use it very
infrequently, and use the types that does not require
diatomaceous earth. There are better ways of fine filtering the
water that are more efficient.

   SAND AND GRAVEL FILTERS  

        Perhaps the best and certainly the least expensive to set
up. A small old aquarium will do (if you don't have one, look in
your local bargain newspaper in the pet section, you will find
them advertised all the time).

        The filter can be set up using a regular canister filter
as well, filled with gravel (or sand, although it is probably
better to use gravel.

        Because sand is finer than gravel, sand filters will
filter much finer material out of the water, but not as fine as
to remove what your filter feeders need. Gravel is probably good
enough and is easier to maintain and clean. Additionally it is
unlikely that anaerobics will start in your gravel filter if you
clean it regularly, and if water flows through it continuously.

        You can use traditional canisters or special canisters,
or you can build one yourself, using a acrylic tube that is
outfitted with a top and a bottom. Since you will need to be able
to access the inside to clean the filter, you must use some
device that allows you to do so. A compression nut is usually
best. Make sure it is all plastic, or if any metal is in contact
with the salt water, it must be 316 SS. If it is not, you should
coat it with some plastic liquid paint, or with aquarium
silicone.

        It is placed in the top or bottom of the cylinder and
tightened. When the gravel (or sand) needs changing or cleaning,
the cylinder can easily be opened, the filter material taken out,
cleaned and placed back in the cylinder.

        Although this type of filter may not be in wide use, it
is one of the most efficient and also very inexpensive to
construct or set-up. Remember to clean it regularly. You must
remove the dirt that you have trapped from the system (the total
mass of water in the aquarium and what is in the sump of the
filter, pipes, hose, etc.).

        If you are not handy, or if you do not want to make the
cylinder yourself, some can be obtained commercially.
Alternatively, use the aquarium with divider method, shown in the
diagram.

   MICRON AND SUB-MICRON FILTERS

        Similar in their effect to the diatomaceous earth
filters, micron and sub-micron filters are extremely efficient at
cleaning up the water mechanically. They will remove even the
smallest matter, especially if one uses the sub-micron (smaller
than 1 micron) variety.

        They often consist of a canister outfitted with a
cartridge, or bag(s), that will not let particles through greater
than the size the bag, or cartridge, is rated for, e.g. 5
microns, 1 micron, 0.65 micron etc... (see also diatomaceous
earth filters which perform a similar type of filtration but use
a different compound, and the reservations about using such
filters expressed).

        At that level of filtration even parasites are filtered
out. Unfortunately so are all organisms and matter that your
filter feeders feed on, and need. As already indicated  this is
not desirable. If you plan to use such a filter, use it only
intermittently and not for extended periods of time.
        It is important to keep in mind also that such filters
put a great deal of back pressure on the pump(s) and that you
will lose more and more water flow, as the bag or cartridge loads
itself with detritus.

        Filters of this kind are rated in both nominal and
absolute ratings. Nominal simply means that they will effectively
remove most of the matter larger than what the filter is rated
for, e.g. 90 percent or better. Absolute means that they remove
all matter larger than the rating. As you can well imagine the
second variety is quite a bit more expensive than the first.

        Several standard canister filters can be outfitted with
special inserts that act as micron filters. This usually does not
make it necessary for most Hobbyists to buy a special unit.

        The better ones, however, are filters specifically built
for the purpose of micronic filtration. One such example is the
Poly-Bio-Marine PSM-1 filter, which can easily be installed in
line, and used in conjunction with the PMA-1 filter, the
molecular absorption type (see Chemical filtration for more
explanations on that type of filtration).

        If you install a micron or sub-micron filter in-line, you
should pipe it in such a way, that it can be by-passed, by
switching valves. This will allow you to run the system without
the micron (sub) filters for most of the time, and run the
filters only when you want to, for short periods of time.

        By leaving the valves that control the  in  and  out  to
the fine filters slightly open, you will allow some water to go
through all the time. This will prevent the formation of
anaerobic activity in those canisters. It is even used by some to
function as a denitrating filter. When doing so, you must make
the water flow through the canister/filter, very slowly.

        Since you will also have to be able to clean the filter,
you will need a total of three valves to perform this. The
illustration clearly shows how to pipe such a system, either with
hard pvc pipe, or with acrylic or flexible pvc hose (better).

If you are not sure how to do so, check with someone who does, or
call somone in the Hobby you know who can explain to you how to
set such a system up.

        These filters put a great deal of strain and back
pressure on the pump(s) you are using. It is, therefore, a good
idea to plan for a pump that can handle that pressure, when
setting up the system.

        These filters only make sense in a small Reef aquarium if
you happen to have one already. I do not recommend it as a
integral part of a basic set-up. Save yourself the expense. And
if you do decide to buy one, get a good quality unit. The PSM is
probably the best you can get and the easiest to service.

   MISCELLANEOUS

        Mechanical filters can be made using any convenient
container and filter floss or gravel, or a combination of both.
This is easy to achieve if you are using a trickle filter at the
same time, as all you will need to do is first flow the water
into that container, and through the media, and then from that
container to the top of the trickle filter.

        A old aquarium, or a plastic bucket if that is all you
have, will do just fine, and will make the filter quite
inexpensive. In fact, if you refer to some old FAMA magazines, in
the For What it's Worth column, you will find many suggestions on
how to set such filters up.

        Without a trickle filter (see biological filtration)  it
is very difficult to use this form of mechanical filter, unless
float switches (level switches) are used as well. This
complicates the set-up and can increase its price quite a bit.

        One tried method that is often inexpensive to install,
consists of using old canister filters, place them in series, and
run them with an old pump you have sitting around. Not the pumps
that came with the canisters, but something stronger than that
as, to push water forcefully through one or more canister
filters, you may need something the equivalent of a Number 2 or 3
magnetic drive pump (brands include Little Giant, March, Iwaki,
and others). Do not use extra strong pumps as the canisters will
not take a very high amount of inside pressure.

        If you do not own such a pump, look in your local
bargains advertisement paper, ask the Pet stores you deal with
for second hand pumps, or call other Pet Stores in your area.
Your local Aquarium Society may also be a good source for
getting equipment you need.

   MECHANICAL FILTER IN SYPHON :

        To bring water down to a trickle filter two methods are
used. Either the surface skimming syphon arrangement, or holes in
the tank combined with a corner overflow box (see The Marine Fish
and Invert Reef Aquarium for a detailed discussion).

        A number of syphon devices have a pre-filter (mechanical
filter) built in to the downflow. That is of course an excellent
way of filtering the water, as it is done one step before the
water enters the biological part of the trickle filter, thus
reducing the amount of detritus that can get stuck there. This is
especially important with certain types of materials used in such
filters, e.g. DLS and similar materials that go by different
names.

        The latter, due to its denseness, can indeed trap dirt
very easily. Such is totally undesirable, as it will quickly lead
to reduced levels of dissolved oxygen, which, as we shall see
later, will stress all tank life, and lead to a system that is
not running at its optimum, and in which disease and micro-algae
will more than likely occur intermittently or, more likely, all
the time.

        Mechanical filters inside syphons are usually made of
coarse foam that traps the dirt. Clean it regualarly. At least
once a week. Remove the sleeve, or twist it loose (as in the
Smit's Natural Reef model and also in a few others), rinse it
out, and place it back in the syphon.

    CONCLUSION :

   You must clean the water with a mechanical filter, and you
should do so before the water enters the biological filter.

   You must clean the mechanical filter(s) regularly, at least
once a week. More often can not hurt, to the contrary.

   You should, in my opinion, not use micronic, sub-micronic and
diatomaceous earth filters on small Reef tanks, and if you do,
you should only use them very infrequently.

   The denser the material inside your biological filter contact
chamber, the more importance mechanical filtration of the water
going to that filter, before it gets there, becomes. Indeed, this
will  prevent dirt getting trapped too quickly, loss of dissolved
oxygen and decay inside the biological filter.

    Several mechanical filters, instead of just one, do not hurt
the system, on the contrary, but are, in my opinion not a
requirement. They just add to the cost of setting up the tank,
unless of course you have them standing around anyway.

   A complete trickle filter with all the required types of
filtration incorporated, and segregated, is the ideal system to
go with for a small Reef Aquarium.

   How such a filter is built and what it looks like may not be
what you have in mind right now. The traditional box-like filters
that have been around for several years are obviously one way to
go, but there are other approaches that we will discuss.
        
          Look for our recommendations on mechanical
filtration later in this book. You may also wish to refer to the
How To section of FAMA magazines, as many ways of fine filtering
have been described there.

        Incidentally, FAMA published all the HOW TO's in book
form. Check with  them for ordering information. FAMA is the
abbreviation for Freshwater and Marine AQUARIUM magazine.

[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]




SMALL REEF AQUARIUM BASICS 
 
BIOLOGICAL FILTRATION


   General Remarks

        What biological filtration is all about, is not the
subject matter of this book. You may wish to refer to general
marine aquarium books if you are not entirely familiar with
biological filtration, or if you want to read up on it some more.

        One not-general-at-all book, but a very detailed one on
marine aquarium systems that we highly recommend is _The Marine
Aquarium Reference-Systems and Invertebrates_, by Martin Moe,
1989. It contains a wealth of information that you will be
interested in, as well as many practical tips and advice that you
will be able to put to good use. Besides that, it explains a lot
of the more theoretical concepts in clear language,
understandable by the average Hobbyist.

        Biological filtration is a very important component of
your total filtration system. As most of you know, breakdown
products of metabolism and decay of protein, produce either
ammonium ion or ammonia depending on the pH of the medium .

        In a marine environment where the pH is relatively high,
a percentage of this ammonium ion is in the form of ammonia, a
very soluble and toxic gas. Even very small amounts of NH3 are
extremely toxic and will cause great stress to the fish and
invertebrates, killing some of them off, which creates more
pollution and more stress.

        To remove this ammonia and ammonium ion nature, comes to
our help with the nitrification process, whereby ammonia is
converted to nitrite, and nitrite to nitrate by bacteria that
will grow spontaneously in the tank, or that can be added
(seeding) when first starting up the tank, to speed up their
proliferation.

        Bacteria grow everywhere, not just in a biological
filter. Please keep that in mind. The size of the bacterial
population is also determined by the amount of nutrient available
to them. Keep that in mind too. Most Hobbyists do not, and think
that once their filter is cycled, they can put a large number of
fish and invertebrates in the tank, without danger, and
immediately.

        That is not so ! It is a mistake very often made, and it
leads to die-offs, disease, stress, and a host of problems. Look
at it this way : a biological filter that is very potent during
the cycle, can only keep sustaining the same amount of pollution
as it had during the cycle. If you increase the load in the tank
to beyond that level, the filter has to readjust and build up
even more bacteria.

        To simplify the explanation : if you had 5 pieces of
so-called live rock in the tank during the first 4 weeks
(i.e.during the cycle), and it required, for argument's sake, 7
million bacteria to cope with the pollution so generated, you
cannot expect those same 7 million bacteria to cope with 10
pieces of live rock (keep in mind that the numbers are arbitrary
and bear no relationship to the real numbers. They are only used
to illustrate a point).

        To cope with this new load you will need even more
bacteria. They will grow spontaneously in your filter, but it
will take a few days for them to appear and neutralize the
increased amount of ammonia (and subsequently the higher amount
of nitrite).

        Each time you add an animal or an invertebrate, more
ammonia is generated and more bacteria are necessary in the
filter to neutralize that pollution. That is the reason for the
often found recommendation : add new tank inhabitants only a few
at a time, and wait several days between each introduction ( your
safest bet is to check for ammonia and nitrite, if none is found
you can add more lifeforms).

        Indeed, doing so let's the filter catch up (meaning more
bacteria grow) without creating undue stress on the animal life
already in the tank. This results in a safe and gradual increase
in the tank's population. If, in addition, you use the
recommended methods for adding fish and inverts, you should not
have any problems with outbreaks of parasitic infestations.

        No one can offers 100 percent guarantees, but if you
follow these recommendations, your chances of not getting any
parasites will be greatly improved. You are, then, also less
likely to lose the animals (and the money they cost you). Marine
Reef, the newsletter, featured several articles on this subject
already.

        A similar remark applies to biological filters that are
started up with several rocks or fish, and then left to run with
far less lifeforms for a while. The filter adjusts to the lower
amount of pollution. If the Hobbyist then decides to place a
larger number of lifeforms in the tank again, the filter will not
be able to cope with this increased load. It will need to
readjust first, and that takes time. If you do not let the
filter adjust, stress will be created and lifeforms will be lost
(or as often is the case, disease will break out).

        This is an important remark to remember with regard to
biological filters ! How long the readjustment phase will take
cannot be predicted. Testing for ammonia and nitrite is the only
sure way to deter-mine whether or not the filter is ready for an
increased load. Both should test zero ppm (or mg/l).

We noted that mechanical filtration is important for two reasons :

   it removes particulate matter before it can break down and
pollute the water,

   it makes the tank look more appealing, by unclouding the
water and removing debris.

Correct biological filtration is very important because it  :

   breaks down ammonia to nitrite (Nitrosomonas bacteria)

   breaks down nitrite to nitrate (Nitrobacter bacteria)

   oxygenates the water for the benefit of all lifeforms and the
filter itself.

   removes a number of unwanted compounds through facultative
aerobic-anaerobic activity in portions of the filter (Wolff
1984).

        Incidentally, and as a reminder that trickle filters are
not some recent development, the first reference to such filters
that I could find is in a book published in 1935, yes that long
ago, called American Sewerage Practice, by Leonard Metcalf and
Harrisson Eddy, Volume 3 of 3, The Maple Press Company, York,
Penna. Call them if you are interested in how large volumes of
water get treated. That book was brought to my attention by
Matthew Cammarata.

        The filters in that book are large, some even very large,
at least compared to what we use in the Hobby nowadays, but the
principle behind their efficiency has not changed an iota over
the years.

        Such biological filters (not necessarily all trickle
filters) can be set up in many ways. All work of course, or
Hobbyists would not have used them for several years now, and
they would not be around in the literature anymore.

        There are however varying degrees of efficiency in the
types, brands and models available on the market. Some just do a
better job than others. You know most of them :

          Canister filters, traditional

          Canister filters, special

          Undergravel filters, regular flow, reverse flow

          Outside box filters

          Trickle filters in many configurations

          and a combination of one or more of the above.

        There are other types of biological filters too, perhaps
not as familiar to you, but they are used by a fair number of
Hobbyists too:

           BioMesh filters

           Ruecksack or Backpack filters (hang-on trickle
           filters)

           Tray Filters, similar to trickle filters

           Outside the tank biological sand filters

           and a variety of intermediate ones, based on the sand
           filter system.

        All of them serve the same purpose : the three reasons
stated above. As indicated, however, some of these filters do a
much better job than others at improving water quality,
especially where it comes to re-oxygenating the tank's water.

        For years in the hobby, especially in Europe, the trickle
filter has made great strides in this country too. In 1985, when
I first imported trickle filters from Germany (from a company
called Nollman Aquaristik, in Sennestadt), hardly anybody even
knew what such filters looked like, or what they were supposed to
do. Nowadays, just looking at the ads in the Hobby magazines,
everyone seems to claim "they" were the first to ever offer this
type of filter (refer too to my earlier remark about the 1935
reference to trickle filters in _American Sewerage Practice_ to
convince yourself that such is merely advertising copy).

        Who was the first, and when, is not important and
germane, what counts is that these filters are extremely
efficient, and that for the purpose we are interested in - high
quality water - they are the foremost filter, and the most
effective at the present time. The variety and number of such
filters now available attests to their success, and to the fact
that both manufacturers, and Hobbyists alike, believe in them.
        
Because I strongly believe that to run a successful Reef you need
such a filter, or a similar type e.g. a hang-on unit (Ruecksack
or some types of conversion units, for instance), we will review
only such filters in this section.  Information on undergravel,
and similar filters, can be found in many other books, as I am
sure you are aware of. Refer to them if you still want more details,
or if you want to review and compare them with trickle filtration.

Inside an appropriate compartment, a medium is placed on
which Nitrosomonas and Nitrobacter can grow in large numbers. The
shape of the box has absolutely no bearing whatsoever on the
efficiency of the filter, although most manufacturers make them
square or rectangular, because round tube or pipe of the size
usually required, would make the filter much more expensive.

When dealing with the shape of a trickle filter, the
important factors to take into account are the following, in my
opinion:

   filters that are too narrow tend to create "channeling" of the
water against the outside panels of the filter, resulting in very
inefficient use of the medium,

   filters that are short, meaning not tall enough, do not
promote re-oxygenation very well, and are therefore not as
desirable. The minimum suggested height of the column of
biological medium is 12 to 14 inches.

Most filters you see are clear, probably because clear
acrylic is less expensive than other varieties. In fact, the
filter would do better if it was not clear, as the bacteria
perform better in the dark (documented in too many articles to
mention).  Nollman Aquaristik, of Sennestadt Germany, which has
been building filters for many more years than anyone in the USA,
builds theirs in opaque PVC sheet. Luebbecke Aquarium who have
used large trickle filters on their 10.000+ gallon system for
many years, uses 3 foot diameter grey PVC pipeline sections.

Another reason may be that clear filters can easily be
looked into, something the Hobbyist likes to do, to determine how
the water is flowing through the medium.

The biological filter compartment should be removable
from the other parts of the filter. This allows for easier
transport and shipping, easier installation, and much easier
cleaning of the other parts of the filter when the need arises
(and it will, believe me, mainly because most filters on the
market do not have slanted bottoms which will require you to
syphon out detritus from time to time).

As the water comes down from the tank to the filter, and
disperses inside the biological chamber, it travels over the
medium and allows the bacteria that grow on them to polish the
water by first converting ammonia to nitrite (one type of
bacterium) and then from nitrite to nitrate (another bacterium).

The better the dispersion of the water, the
better the water is spread over the medium, and the better the
filter will be able to clean up the water. That should be
obvious. Not only is filtration more efficient, but by using the
medium more efficiently you will need less of it. This can save
you quite a few dollars as most of the media are still relatively
expensive.

Additionally, less medium fits in a smaller filter, and
that too will save you money. It will also make more space
available underneath the aquarium, and since space there is at a
premium....

Because you do not want to have to clean the biological
filter - in doing so you would destroy a large amount of bacteria
- the medium should allow a good throughflow of water, and not
trap dirt that may have slipped through your fine filters
(mechanical filtration). It isn't supposed to, but some will. If
it gets stuck in the medium, in the long run you are looking at
cleaning it. We already stated that such is not desirable at all.

Dense material will plug up no matter how well you
filter. The main reasons for this is that fine particulate matter
not trapped in the fine filters will eventually clog certain
areas of your dense biological filter, creating anoxic pockets.
When oxygen levels are low, or non-existent, decay is proceeding
anaerobically, and hydrogen sulfide is produced. This will pull
your water quality down very quickly.

In fact, if you were measuring redox potential levels,
and they are low, even though you are using a considerable amount
of ozone, the likely reason is that small amounts of hydrogen
sulfide are pulling the redox down, because of the reductive
power of hydrogen sulfide. Increasing the ozone may not even
help. You must  eliminate the H2S to bring the redox potential
back up. There exist of course many other reasons for low redox
potential, some of them will be covered elsewhere in this book,
especially in the Maintenance Section.

   Components of a Good Trickle Filter :

We already mentioned the biological compartment. Several
features of this compartment are important, because they add to
the efficiency on one hand, and to the ease of installation and
servicing on the other :

    Because acrylic warps easily when in contact with
water, good reinforcements of the side of the biological
compartment are very desirable. Beware of filters made out of
very thin acrylic or similar materials. They will warp, and may
split on you, unless reinforcements have been added to prevent
this from happening.

    A removable lid is a plus. Dirt will get into the top
of the filter whether you like it or not. When the lid at the top
is removable, it will be very easy for you to remove that dirt.
The lid should also be reinforced, or made out of glass (best).
If you can't get to the top, the dirt will do two things : it
will decay and reduce water quality, and it will plug up holes in
the drip plate (if that is what you are using, and you should).

    At least two air inlets are recommended. The bacteria
inside the filter are aerobic, meaning that they require oxygen
to perform. Blowing a good flow of air into the filter is
therefore very desirable. The better the air is spread out, the
better the filter will operate. I usually recommend that
Hobbyists use a air pump such as a Whisper 1000, or stronger
(e.g. Wisa), and blow all the air inside the biological chamber,
using both the air inlets. If only one is available, you may wish
to drill a second one, push airline tubing through it, and then
pack a little aquarium silicone around the hole, so no water
comes out. Blowing more air will not hurt, to the contrary. To
convince yourself of the benefit of doing this, run air into the
biological chamber, note the redox potential, now shut off the
air, and then watch what happens to the redox potential: it will
go down (Bepko, 1988, Thiel, 1988). It may even go down quite a
bit. You must blow the air into the chamber above the water
level, directly into the column, not through an airstone placed
in the water underneath the biological chamber.

    The height of the chamber should be at least 12 to 14
inches. Shallower filters will work, but you will need to flow
more water through them. Because there really is a limit to how
much water can be flowed through a small biological chamber.
Excessive current through the filter will wash off some of the
bacteria, and result in a less efficient filter, less
oxygenation, and a smaller biological colony.

    The width of the chamber should be no less than 8
inches. Narrower filter chambers channel too much water on the
sides rather than through and over the medium used, and that
reduces the efficiency of the filter.

    Use a filter with a drip plate rather than a spray
bar. The reasons for this are explained in the section on drip
plates, later in this section.

    The chamber should not sit too deeply in the sump.
This will keep all the medium out of the water in the sump.
Bacterial beds that are out of the water are more efficient at
handling ammonia and nitrite. Wolff (1984) suggests that the
efficiency goes down to less than 60 percent when the medium is
submersed.

    Larger sumps are to be preferred. They increase the
total volume of water in the the system, and make it easier for
you to use a powerful pump. If too little water is in the sump,
evaporation will lower its level quickly, and if, as you should,
you are using a float switch, the pump will stop regularly, and
eventually altogether when the water level is real low.
 
Larger sumps also have more space for other devices that
you may want to add to your system and that you may wish to run
with a power head.

    The sump should preferably be reinforced too, as this
will prevent warping and possibly splitting months down the road.

    Compartments built in the sump are always a plus.
They allow you to easily add certain compounds to the system.
Make sure however that the compartments are built in such a way
that the water coming from the biological chamber must flow
through them, not just over them. Whatever you place in them will
work better if the water has to go through the compound
completely.
 
    Depending on the size of the tank, you will be using
a particular pump. Check the in and outlet sizes of the pump.
Make sure the hole in the filter is of the same size, or larger,
than the size of the pump intake. Re-drilling an existing hole is
not the easiest and safest thing to do. If a bulkhead fitting is
already included you will not have to go out an buy one. If you
do, buy a real tank fitting, not a rigged male/female fitting
type arrangement.

    Built-in  foam fractionators - protein skimmers - are a
definite plus, but they must be of the size that your system
requires. Not some flimsy little skimmer that was built to fit
the filter rather than the tank! This is most important because
undersized skimmers will be a real problem for the tank, and are
one of many reasons for the appearance of red algae. See the
section on skimmers for more details on sizing. Don't lull
yourself into thinking that you have one if the filter you bought
has a real small skimmer built into it. Stick with either an
outside columnar one, or a built-in Venturi skimmer, and make
sure that you can use ozone with it, because you probably will
want to, or need to.

    A sump with a slanted bottom will allow mulm and
other detritus from being moved forward by the current, making it
much easier for you to syphon it out. Mind you, mulm is
technically speaking inert, and should not affect the water
quality any longer, it is the detritus that needs to be removed.

    Certain filters have a built-in tray for electrodes.
That is handy if you are using them, but in the basic system that
we are setting up, we will not.

    Whether the sump has a lid, or not, does not really
make much of a difference. Most of the evaporation is not from
the sump, but from the aquarium itself. It makes the filter look
more finished though.


   Sizing the Trickle Filter :

From an economics standpoint this is a most important
section. Buy a filter that is too large and you spend more money
on the filter and also on the internal medium. Buy one that is
too small, and your water quality will suffer, and you may lose
fish, invertebrates, and ultimately money too.

In my estimation, buying the wrong filter will end up
costing you two to three hundred dollars more than you should
have spent. Of course, building your own filter would be the
least expensive way to go. Plans are available in the magazines,
and were also published in my other books.

The ultimate size of the filter will largely depend on
the internals (biological medium) you use. The better the medium,
the less of it you will need, and the smaller the filter will
become as a result.

Here are my suggestions for sizing, providing you use
either Bio-Techs, or Bio Blocks. Both are available from dealers
nationwide, and cost about the same per gallon volume of the
material.

   Tanks up to 40 gallons : you will need 4 gallons of
   internals.

    Tanks up to 55 gallons : use any trickle filter that
    can hold 4.5 gallons of the above materials.

   Tanks up to  70 gallons : you will need a filter that
   can hold 6 gallons of biological filtering medium.

   Tanks up to 110 gallons : 7.5 gallons of capacity
   required.

    Tanks 125 - 135 gallons : 8.5 gallons of internals
    needed.

    Tanks 150 gallons :  10 gallons .

The above numbers are lower than what you normally will
find recommended because they are based on tests, not on
advertising claims made by various manufacturers of plastic
filtering media.

They assume you follow the directions in this book : most
importantly that  good dispersion is achieved by means of a
"drip plate" of the kind we describe. This means that you may
have to slightly modify (easy and explained later) the drip plate
that comes with the filter you have bought, or are using now.

   Why are these recommendations lower ?  Over the last 5
years I have had the opportunity to personally use the following
media: German blue balls, Jaeger Tri-Packs (2 sizes), Bio Cubes,
Bio-Techs, Pall Rings, Norton Rings, Plastic haircurlers,
EfigroB, Raschig rings, Bio Discs, Cut PVC pipe, Cut acrylic
chips, Gravel trays, Sand trays, Beads, Dolomite, and others
still.

Doing so gives one a pretty good experience with which
materials provide the kind of filtration required for Marine Reef
tanks, and allows for fair and educated comparisons of their
respective merits.

The following criteria guided me in deciding
which internal plastic medium to use myself, and recommend to
others :

  Dissolved oxygen levels after all ammonia and nitrite
  was converted.

  Speed at which ammonia was converted to nitrite and,

  Speed at which nitrite was converted to nitrate,

  Gaseous exchanges : e.g. was the CO2 level within the
  norm?

  Do they trap dirt, how much, and what size ?

  Once dirt is trapped, how long does it stay in the
  filter ?

  Does water flow evenly, continuously, over the medium ?

  Does channeling occur, and if so, do what degree ?

  Does the material you are using stack up ?

We have not recommended a product called pax, because it
seems to trap more detritus than we feel is safe for your system.
Unless some modifications to that material are made we feel that
it is not a "best buy" for Reef tanks. It does well for fish-only
tanks however. Biological filtration in Reef Tanks requires
attention to details, not just "surface area" or "dispersion
ability."  Select what you buy very carefully.

   Important Media Considerations :

The following qualities are important considerations when
buying internal plastic biological filtration materials (usually
Polyethylene, or plastic, as it is generally referred to)  :


   the material should not trap dirt and debris. This
   includes pieces of food, algae, and any other free floating
   particulate matter.

   the material should allow good gaseous exchange by
   braking up the water in really fine streams and drops.

   the material should have a relatively large surface
   area. You will need somewhere between 2 and 2.5 square feet of
   biological filtration area per gallon of water in the tank. The
   exact amount, whether the lower number or not, depends on the
   load in the tank. If the distribution of the water over the
   medium is really maximized, you can go as low as 1.25 square feet
   of surface area per gallon of water.

   the material should be totally inert. No leachings
   whatsoever are allowed.

   the material should maximize the utilization of the
   biological chamber. This means that there should not be large
   gaps between the individual media pieces.

   the material should be permanent, meaning that it does
   not deteriorate, and thus never needs replacing.

    the material should be unbreakable, so that no rods,
    or pieces, break off and ruin the pump impellers and volute, and
    possibly the inside of a chiller, if you were to use one (not
    part of a basic system of course).

   it should not be too rough as that would result in
   dead bacteria being overgrown by live colonies, which is not
   desirable as it will lead to very small amounts of anaerobic
   activity underneath the live active layer, possibly killing some
   of the live layer of bacteria off, or reducing its potency due to
   anaerobic activity by-products (Thiel, 1988).

   Drip Plate or Spray Bar ?

The controversy surrounding this topic has been going on
for quite some time now. Very simply, it is my educated opinion,
based on extensive testing, that drip plates perform better in
trickle filters than  spray bars do, because :

   they distribute the water more evenly,

   contain dissolved gasses better, and

   are not subject to clogging ,

  and slowing down, the way spray bars are.

We, therefore, now recommend drip plates in trickle
filters, and have, after trying many variations, arrived at the
drip plate that we feel performs best :

  Hole size of 3/16"

   Holes separated by 3/4 inch spaces,

   Plate grooved for better water distribution,

   Hole size commensurate with flow rate,

   Holes tapered at the top of the place.

   No holes within 1 inch of all filter sides, to reduce
   channeling

You can modify an existing drip plate by plugging holes
that are too close to the sides with aquarium silicone, and add
holes if necessary. If the plate can be removed you can do so
rather easily, if not, you must drill the plexiglass plate while
leaving it where it is. Use only acrylic drill bits! They will
prevent cracking of the acrylic when you drill through it. They
are not expensive, and are sold at most stores that sell acrylic
in custom cut sizes.

To position the holes correctly, draw lines with an
acrylic scratching tool, 3/4" apart length wise, and 3/4" apart
cross wise. Then drill holes where the lines cross (see drawing
below).

To obtain tapered holes, use a small countersink
drill bit after you have drilled the holes. This gives the
tapered effect which will improve the flow of the water
downwards into the biological chamber, and over distribute it
better over the medium you are using.

Although the drip plate may not appear to you as a
significant part of the trickle filter, it is a very important
one. Indeed, by selecting the correct one, or modifying it as we
suggested, you can ensure a much more even dispersion of the
water coming down from the tank, over the medium that you are
using.

That in itself assures a more efficient biological
filtration and, ultimately, a greatly improved water quality, the
purpose of using a trickle filter to begin with.

    Retrofitting for a slanted bottom :

Most units on the market have a "flat" trickle filter
bottom. As we have seen, this does not promote the forward moving
of detritus and debris. Retrofitting an existing filter is not
complicated at all :

   Measure the inside dimensions of the sump very
carefully. The match of the plate you will be adding, with the
inside of the sump must be exact. Measure from the back of the
filter, coming towards the front, up to where the biological
chamber ends. The plate only needs to be long enough to fit
underneath the biological chamber.

   Acquire the piece of acrylic from a plastic dealer in
your area.

   Place the plate in the sump in such a way that it
slants forward at an angle of a few degrees only.

   Dry the sides where you will need to glue properly. This
is really important because glue does not stick if the sides are
still moist. Go over the sides of the filter with paper towels
several times.

   Use aquarium silicone to glue the plate in place. Glue
with care because you need a very good seal. No water can be
allowed to get underneath the plate. It would stagnate and create
anaerobic conditions.

   Let dry for at least 75 minutes, preferably somewhat
longer. Since not a great deal of pressure will be exerted on the
seams you glued, you will not need a 24 hours curing period.

   The force of the current over the slanted plate will
now move the debris and detritus forward, and you will be able to
syphon it out very easily. In the process you will prevent it
from decaying in the system and reduce your dissolved oxygen
levels.

   Adding Compartments to the Sump :

Rather than buying canister filters to add certain water
filtering products to your tank, you may wish to add compartments
to hold these same compounds.

Included in this list of compounds are, for instance,
X-nitrate, Poly Filters, molecular absorption discs, resins for
chemical filtrations, and others.

   decide on the size of the compartment you will add,

   measure the exact dimensions of the acrylic pieces
   needed,

   obtain the pieces and make sure you have enough
   silicone sealer,

   use any one of the two designs below to build your
   compartment,

   place the compartment in the filter, and add the
   compound.

Type 1 :  Place the unit off the bottom of the filter by resting
it on a ledge made of small blocks on all corners. For most
efficient set up glue the corners onto the compartment. Use
acrylic cement, or aquarium silicone. Place floss or screening on
the bottom to prevent the material from getting through. Type 2
No base (bottom). The compartment rests on the bottom of the
sump. Drill holes all around the base to let the water get out
easily. Quarter inch holes usually will do. Remark : Clean the
material regularly to prevent it from clogging and restricting
the water flow.

Remember to change the material that you are
using in these compartments on a regular basis. Most exhaust
themselves as they do what they are meant to do. Follow the
manufacturer's instructions in this respect.

If you do not attach (glue) the compartments permanently
to the base of the sump, you will be able to remove them, and
replace them with a larger (or smaller) one, should the need for
that arise. Not attaching them will also simplify cleaning them,
as all you will have to do is remove it (them). Always remove
them very slowly, to prevent detritus trapped inside from getting
into the sump of the trickle filter, and being sucked in by the
pump(s).

   Fittings on the trickle filter :

     A good trickle filter should come equipped with all fittings
needed to hook it up.

     This includes a fitting a the top, a hook-up for
airline tubing, and one where the pump needs to be attached.

    It does not include ball valves and check valves,
neither does it include float switches and the like, except
perhaps in the top-of-the-line units.

   If the filter has a skimmer built-in, a hook-up for that
should be provided as well. Again, make sure that the skimmer
can be used with ozone if you are planning to do so, and that it
is placed in such a way, that flowing the outcoming water over
carbon is easy.

It should also not allow air-ozone from getting into the
back compartment where your biological medium is, as ozone will
destroy the bacteria in the biological filter.

   To save on the total height, look for a filter that
has a 90 degree angled fitting for the water inlet at the top.

   Float Switches :

There are many uses in the Hobby for float switches.
Level control is an important feature of a modern aquarium, and
you should certainly consider adding it to your tank, especially
since inexpensive models have now become available.

Keep in mind that water levels can be controlled in
various ways

   prevent water from getting too low,

   prevent water from rising too high,

   or a combination of both, using double switches.

Float switches that control the "low" do two main things
for your system's stability and protection :

   They prevent the pump from running dry when the water
level in the sump gets reduced because of evaporation, or when
you remove water yourself, for whatever purpose you may do so
(for example when changing water).

   They even out (balance out) the amount of water going
up to the tank, and the amount coming down to the filter as, if
the level in the sump drops too much (you regulate the height at
which the float switch triggers) because more is going up than
coming down, the float goes down, and stops the pump for a short
period, until the level in the sump goes back up.

Float switches that control the "high" serve the
following purposes :

   add from a reserve vat. When the level in the sump
reaches the desired level (which you decide on) the float shuts
the pump that is adding water down, remotely. Indeed, the pump is
in the reserve vat, the float switch is in the sump, and senses
the level as it goes up.

   shut down a solenoid valve that controls water coming
a large skimmer to the sump, for instance. You are unlikely to
use this feature in a basic system, however, because of the high
cost of setting this up. A large and reliable solenoid (e.g. 1
inch in and outlet) costs close to $ 450.00.

When in the market for a float switch, shop around!  You
should consider the following types that are commonly available:

  Reed switches

  Mercury switches

  Infra-red switches

All have advantages and disadvantages :

  Reed switches are inexpensive, but harder to install,
and may require that you operate them via a special relay. This
does not make them very practical for the average Hobbyist to
use.

  Mercury switches are more expensive. They are extremely
reliable, but can be rather bulky and are not as easy to find.
Installation is not difficult, but will take a little more time.

  Infra-red switches are very reliable, cost even more,
but are extremely easy to install. If you are considering this
type make sure that it can sense through the scuzz that builds up
on the side of the trickle filter sump. Of course, they only work
with transparent filters.

The key when using float switches, is to make them
trigger at the correct level. With mercury and infra-red switches
this is real easy, with reed switches it is a little more
complicated and time consuming.

The trigger point should always be at least 1.5 inches
above the top of the intake hole of the pump. This to prevent air
from being sucked into the pump because of a vortex that will
form around the intake area, if the level in the sump is too low.

Air in the pump volute and impeller area, makes the pump
run much hotter, and heats up the water too. Additionally the air
may be broken up by the impeller, and extremely small bubbles may
form. These are pushed into the tank, making it look real
unsightly. Such small bubbles can also cause nitrogen gas bubble
disease.

Small, reliable, float switches can often be obtained
from Marine Supply companies and shops. They are usually operated
in conjunction with bilge pumps on boats. Make sure that they
have no metal parts that can come in contact with the water in
your sump, except if the metal is 316 SS. Additionally, they must
be made to run on 110 volts, not 12 or 24 volts. 


[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]
SMALL REEF AQUARIUM BASICS
    
Hard Piping or Flexible Hose ?

Although many Hobbyists prefer hard pvc pipe for all the
hook-ups and connections, flexible hose is just as good and
reliable. Additionally, if you source the flexible hose from a
discount supplier, you will save quite a bit of money.

You will still need  ball valves and check valves, of
course, but you can mail order those from companies such as U.S.
Plastics in Lima, Ohio, or other ones that advertise in the
aquarium magazines. Alternatively, get them from a local plumbing
supply house, or from swimming pool places. Shop around! Prices
can vary tremendously, as some of you may have found out.

Hard piping requires that you familiarize yourself with
how to glue PVC pipe together, and also which fittings will do
the job you are trying to accomplish. Check the Marine Fish and
Invert Reef Aquarium book, the chapter on Fittings, if you are
not familiar with them.

Flexible hose installations are usually simpler to
perform, quicker to finish, but do not look as "tidy". Remember
to always use hose clamps wherever you join flexible hose to an
instrument, a device, or to pvc pipe and plastic fittings. This
is most important to prevent leaks, and ensure that the hose will
not slip off as a result of the internal pressure building up
inside the system. If that happens to you, you will have a lot of
water on the floor!

   Fittings other than on the filter :

You will need at least one ball valve and at least one
check valve per water line running back to the aquarium, to
ensure that  your system is totally safe.

The ball valve will allow you to adjust the water flow
going back to the tank from the filter, preventing too great a
flow, and the check valve will prevent back syphoning through the
line running up to the tank, should the pump break down, or
should a power failure occur. More details can be found in my
other two books as well.

Shop around for these and other valves you may be using,
as  mark-ups vary widely from dealer to dealer, even from
plumbing supply place to plumbing supply place.

Place the ball valve about 1 foot away from the output of
the pump (see diagram). Place the check valve either inside the
trickle filter, or between the filter and the system's main pump.

If you place the check valve inside the sump, right on
the pump intake, you will be able to prime the pump (getting the
air out) much faster and in an easier manner. When you do so, you
should cover the intake side of the check valve with a special
screen, which converts the check valve to a so-called foot valve.

Depending on how elaborate your system is, or becomes,
you may find it necessary to install more than one ball valve and
more than one check valve. Refer to The Marine Fish and Invert
Reef Aquarium, and also to Advanced Reef Keeping, for more
details on how to set such systems up.

Some type of installations need 2 lines of water flow,
e.g. one to the aquarium and one to the protein skimmer. This is
done by means of a Tee-fitting, either barbed, or straight PVC.
You may then need a second ball valve to adjust the amount of
water going to the skimmer.

A typical installation, e.g. using the Thiel Aqua Tech
filter, looks like this :

Only one ball valve is shown in the return line to the
tank. That usually suffices, but as an extra safety, especially
to make servicing of the pump itself easier, you may want to
include an inexpensive ball valve (usually called throw away
types) between the pump and the sump of the trickle filter. This
will allow you to take the pump out of service without having to
lower the water level in the sump.

Although they will cost more money, "true union valves"
are a much better choice than regular slip/slip valves. They are
also easier to maintain, can be opened, and allow for easy and
quick disconnection of pipes, should the need arise.

   Adding Canister filters

Earlier I referred to installing extra compartments
inside the sump of the filter. Not everyone wants to go to the
trouble of doing so, or may not need to, because they have one or
more canister filters standing around from previous filtration
systems.

Canister filters obviously make great container/pump
combinations for compounds through which the water needs to
flow. I use them myself, and prefer the Eheim models 2217 and
2017 because of the large size of the canister itself. But there
are, of course,  other models available, for example Marineland's
Magnum, and various Fluval types, including their large 403
model.

Since we are trying to set up a Reef Tank that will be
correctly equipped on a smaller budget, you may want to shop
around for canister filters. Try the bargain newspaper ad in your
area. Or check if your Pet Store can sell you used ones.

Remember to change whatever compound you are using
regularly. If, for instance, it is supposed to remove nitrates,
as X-nitrate does, make sure that you test for nitrates from time
to time, to double check whether your nitrates are still going
down, or at least remain stable. If they do not, you obviously
need to replace the compound. Using quick disconnect valves will
make this a much simpler process.

   Flow rates through Filters and the Tank :

First of all, you must differentiate between water flow
through the system and water current in the tank. The former is
pretty obvious: how much water is flowing through the filter,
e.g. per hour. The latter represents the amount, and strength, of
flow in the tank itself.

They are not necessarily the same. In fact they shouldn't
be. It is often recommended that you cycle the water content of
your system anywhere from 2 to 6 times per hour through the
filter. I find that latter figure much too high.

My recommendation in The Marine Fish and Invert Reef
Aquarium was, and still is, that the water content of the tank be
flowed through the biological filter 3 times per hour. More, and
you risk bacterial wash-off, less, and you may not get enough
biological filtration.

If you want more current in the tank itself, e.g. to
simulate the wave action and movement around the Reef, use one or
several power heads. One power head on the short side of the tank
will usually do, but you can get more sophisticated, and use
several that alternate, using an Ocean Motion machine, or
similar. This was described in much more detail in Advanced Reef
Keeping Made Simple.

The key to get the right flow rate, is to select your
pump carefully. Ratings for pumps are given, most of the time
anyway, at 0 feet of head, meaning when no back pressure
whatsoever exists.This can mislead you, inasmuch as you will be
putting back pressure on the pump, and quite a bit of it, once
you operate the tank . Here are just a few reasons for "head"
(also called back pressure):

  Height difference between the level of the pump itself
(where it is positioned), and the water return level (how high up
the water is being returned, meaning to the tank.

  The type of pipe or hose used. Is it of the same size
  as the output size of the pump, or are you downsizing

  Are you downsizing the pipe or flexible hose elsewhere,

  is the intake pipe or hose the same as the pump
  fitting,

  are you using many fittings, especially 90o ells and
  45o ells (angled fittings), as they reduce the flowrate greatly ,

  are you returning the water to the tank from the
  bottom, or from the top of the tank,

  is the pump pushing water through canisters, or other
  filters, that restrict the flow, especially once they start
  plugging up,

  are you using a micron, or submicron, filter in-line ?

Any and all of those, but usually a combination of them,
added to frictional head, reduce the output of the pump, and
result in the true output being quite somewhat lower than the
stated output at zero feet of head. Frictional head is the head
produced by the pipe or hose itself.

You should therefore think carefully before buying a
pump. More so even when you plan to use the pump to run
additional devices that require a good flowrate as well, and put
additional back pressure (head) on the motor.

Talk to people in the Hobby that you respect, and whose
opinion you value and trust, e.g. a Pet Store owner or employee,
someone at an Aquarium Society, a manufacturer, etc. Explain
exactly what you are planning to do, then decide on which pump to
buy.

Presently a lot of people use the Iwaki brand of pumps. I
was responsible for introducing those pumps to the Hobby in 1987
on behalf of another company, and they had very good success with
them. I have used many models myself, but have continued to look
for a more aquarium specific pump, not one developed for the
photographic chemical processing and similar industries.

This has led my company to putting together our own
pumps, The Tech - Z series, labeled Za, Zb, Zc, Zd and Zz,
putting out respectively 300, 600, 900, 1200 and 2400 gallons
per hour. All these pumps have totally encapsulated impellers
(polypropylene), use a special form of cooling and run very
"cool" as a result, and incorporate only Viton seals. All these
pumps carry a full one year warranty to boot.

Other brands you may wish to consider, US made ones,
include Little Giant, March, Teel, and if you need a strong pump,
Hayward. The latter only if you are using 1.5 or 2 inch pipe, and
running a real large system. This is not something you would be
doing on a small reef tank.

For medium type flow rates I strongly recommend the "Aqua
Pump", a 3-speed model that is excellent for running the kind of
tank that we are looking at in this book. It is super quiet, can
be adjusted for output, and is made of a combination of 316SS and
a plastic volute, totally salt water safe. This is definitely one
of the pumps to consider for smaller systems.

It is also an excellent pump to run columnar skimmers
with. I have used the Aqua Pump with 30", 46" and 84" skimmers,
running the pump at respectively, 2nd, 2nd, and 3rd speed. In all
cases it performed exactly the way I wanted it to and, combined
with 2 airstones in the skimmers and a good air pump, it never
let me down.

You must keep one important fact in mind when selecting a
pump : the life of the animals and invertebrates that you want to
keep, and for which you paid good money, depends on the pump that
you ultimately select, running 24 hours a day, for many many
years, hour after hour, day after day, month after month. Do not
overlook this, invest in a good pump. Don't take any chances.

Pumps need to be cleaned from time to time, especially if
its intake in the sump is not outfitted with a fine filter.
Schedule it as part of your maintenance routine. Once every 3
months is probably a good time frame. Additionally, open and clean
the pump and impeller, any time you know for a fact that a large
piece of dirt got into it.

Some general recommendations on installing and piping pumps:

   Do not reduce the output side (pressure side) of the pump
right at the pump. If you must reduce it, do so at least 18
inches away from the output fitting on the pump.

    Never reduce the pipe going to the pump intake side (suction
side). You will cause cavitation, and very small bubbles will
always be visible in your tank because the water breaks up and
the air comes out of it.

    Buy a pump with at least 25-30 percent more rated output than
what you feel you will need to run your tank. This will help
offset the pressure head loss in output, and give a better flow.

    Place the pump at the same level as the bottom of the sump.
Not higher. Pumps sold for aquarium use do not "lift" water very
well and you will strain the motor one one hand, and lose flow on
the other, if you do. Additionally, it will be very difficult to
prime the pump (get it started).

    Often pumps can be used in only 1 or 2 positions. Check to
make sure that the one you are using is an allowable one.
(horizontal, upright, at an  angle, sideways etc.)

    Place pump on a thin piece of rubber, or foam, to reduce
vibration and noise.

    Clean your pumps volute and impeller at least once every 3
months.

    Never let pumps run dry! You will hear this often, but it is
still done.

    If you pipe the pump using hose barbs and flexible tubing, use
clamps as well, to prevent the hose from being blown off the
barb, because of back pressure.

    Preferably use a float switch to protect your pump.

    Make sure no water falls or runs on the pump. If it does,
clean up the water as soon as you can. Salt water is highly
corrosive, and will ruin your pump in no time. Protect your
investment, take good care of your pump.

   Water Returns : One, Several, with or without bottom holes

Water can be returned to the top or bottom of the tank,
and you can use one or several water returns. How you set this up
in your own tank will determine how you can populate the tank, as
you do not want to cover up the water returns with rocks.

In smaller to medium size aquariums such as the ones
discussed in this book, one water return is enough. Whether you
return the water from the top, or whether you pipe it in through
a hole in the bottom is entirely your decision.

  Figures  A   B   D  (see previous page)

Two water returns : the white hole is one, and the second
one is through pipe, represented here by a thick black line. The
entry point through the glass can be on the left, the right or
the middle. In the former two cases you would use a 90o angled
fitting coming out of the bulkhead (also called tank fitting), in
the latter case you must use a Tee fitting, and capped-off pipe,
going in either direction. The pipe in the middle, returns water
underneath the rock formations and pushes the dirt out, so it can
be filtered out or removed with a syphon hose, if you wish to do
that.

D shows the same arrangement, but with the pipe placed towards
the back of the tan and the hole on the other side. Which
configuration you use is entirely up to you.

  Figure  C

Three water returns : one on either side of the tank, and
one underneath the rock formations to prevent water from
stagnating there. The fittings used are described in A  B  D,
above, and more details can be found in Advanced Reef Keeping I,
also by Albert J. Thiel.

As already indicated, most Hobbyists will not need to
drill holes in their tanks and can safely return the water from
the top. Angle the jets downwards to stir up the bottom layers of
water and bring them to the surface for better re-oxygenation.

Returning it from the bottom require more work,
and the tank must be drilled. This is easy in an acrylic tank and
somewhat more complicated in a glass tank. Some Pet stores now
drill holes for you, or you can check with local glass dealers.
As long as the bottom glass is not "tempered", drilling one or
more holes is not really a problem.

The positioning of the return holes varies depending on
whose recommendations you follow. Here are two possible suggested
ways. I use the one with the two returns, one under the rock, and
one at one end of the tank returning water from the bottom,
against a side pane.

Sometimes spray bars are used to disperse the water over
the water at the top of the tank. That may seem like a good idea,
but it does not really create a great deal of water current and
movement inside the tank. It should, therefore, in my opinion not
be used in Reef Tanks.

    Corner Overflows or Syphons-Surface Skimmers?

To bring the water from the tank to the filter, Hobbyists
use either corner overflow boxes or automatic syphon surface
skimmers.

The use of corner overflows is rather widespread. Some
tanks are sold with the overflow built-in, but more than likely,
if you want to use that system, you will have to modify the tank.

Again, you will need a hole in the bottom of the tank (or
the back, or the side, but obviously inside the overflow
arrangement). You will have to build the overflow by using either
2 plates of glass, or 2 plates of acrylic to make a square or
rectangular box (or one plate to make a triangular box, another
possible arrangement that is not shown).

To affix the plates you will use aquarium silicone in
glass tanks, and acrylic glue in acrylic tanks. Get plates of the
same thickness as the aquarium glass or acrylic, using 3/8" as
the maximum. This means that if your aquarium is made of 1/2S
inch glass or acrylic, 3/8" will still do for the overflow. A 4"
by 4" box is usually large enough for most tanks.

Because of the work involved, and the difficulty that you
may have in your area to get glass drilled (acrylic is easy, and
you can do so yourself with a good hole saw) many Hobbyists
resort to the use of a syphon surface skimming arrangement.

There are quite a few on the market. Check around, and
look for the following features :

    Can it handle the flow rate you are looking for ?

    Does it have a pre-filter built-in ?

    Can the pre-filter easily be removed and cleaned ?

    Is it glued properly, or do you see bubbles in the
    seams ?

    Is it easy to prime the first time you are using it ?

    Does it keep its prime, even if the pumps stop ?

    Will it fit over the ledge of your tank ? In glass
    aquariums such is usually not a problem, but in acrylic
    tanks with near complete tops, it often is.

    Will it skim the surface of the water in the tank and
    remove unwanted oily material, and floating particulate
    matter ?

These are all important considerations. Do not select a
model too hastily. Look for at least most of the above features,
especially the automatic re-starting one (meaning it keeps its
prime even if the pumps stop). Having a pre-filter that can
easily be serviced is also important.

Building your own is a consideration, but probably not
worth the trouble. There is a large choice for you to select
from, and in various price ranges. Buy only units that skim the
surface properly, by means of a little box with indentations
(tooth or comb-like) that hangs in the tank.

If you are planning to run more than 350 gallons per hour
through the surface skimmer syphon, the one you buy should have a
1 inch hose adapter going to the filter. If it doesn't you may
not be able to run your pump at the speed you want.

Of course, the unit you acquire should have a barb, or
nip, in a convenient place (usually at the top), for you to be
able to prime the syphon without much difficulty. The
instructions should tell how to do so.

Clean the pre-filter at least once a week, lest it will
start restricting the water flow down to the trickle filter,
which will result in your pump stopping if you use a float
switch, or running dry if you do not, and possibly failing, or
running very hot.

Buy the right syphon-surface skimmer the first time
around. You will save yourself both money and time, indeed,
re-piping the system to replace the syphon is not something you
want to look forward to.

If you decide to drill holes, to return the water to the
tank, which in my opinion is not necessary in small and medium
systems, make them at least 3/4 inch pipe size. This means the
hole will have to be 1 inch, to accommodate the bulkhead-tank
fitting.

    Drip Systems as part of the Trickle Filter :

Although not something that you will find in too many
filters, it is a nice and helpful addition. Use them to dispense
liquid carbonate hardness (KH) generators, vitamins, Kalkwasser
(Limestone water), even fertilizer if you keep a lot of
macro-algae. In most cases, and because drip systems can only be
regulated down so low, you will have to dilute what ever product
you are adding before putting it in the drip system.

For more details on how to do so, and how to set up
manual drip systems, we refer you to "Advanced Reef Keeping Made
Simple"  and also to "The Marine Fish and Invert Reef Aquarium"
(6th or later printing), both by Albert J. Thiel.

    Improving the Efficiency of your Existing Filter

Since many Hobbyists already own a trickle filter, we
receive many phone calls at "Marine Reef", the newsletter
published by Aardvark Press, enquiring how one can improve the
efficiency of an existing system. Since we are setting up a Reef
Tank using only  the minimum basic equipment required, it is most
important that all the components of this system run at their
optimum efficiency.

Here are a few  suggestions :

   Blow more air into the biological chamber.
Using regular aquarium air pumps, it is not possible to blow too
much air in the chamber. Run the air through carbon first, to
clean it.

   If you are not blowing air into it yet, start doing
so, and make sure the drip plate is vented. Usually this is done
by means of a piece of half inch, or three quarter inch, pipe
sticking up from the drip plate. This will prevent an airlock
from being created inside the biological chamber, should the
water level in the sump rise to where the air can no longer
escape through the bottom.

   If some of the media in the biological chamber is
submersed, adjust the water level so it is out of the water. The
efficiency of the filter will increase by over 50 percent. We
guarantee it !

   Clean the sump of accumulated debris and detritus,
this will increase dissolved oxygen levels and improve the water
quality,

   Switch to a different medium inside the filter. For
example, if you are using DLS, switch to one of the plastic
filtering media. We highly recommend Bio-Techs  and Bio Blocks.
If you are using trays with dolomite or crushed coral, switch to
a plastic filtering material as well. If you don't switch, clean
the trays one at time, to remove accumulated detritus, at one
week intervals, to prevent the total loss of the biological
filtering bacteria.

   Switch from a "spray bar" filter to a "drip plate"
filter type; better gaseous exchange will take place, with the
inherent improvement of the water chemistry,

   If you are already using a drip plate, improve its
efficiency by using some, or all, of the recommendations we have
made earlier. For example, increase the number of holes, but use
smaller ones, and make the holes tapered.

   Add compartments for products such a Poly Filters,
Chemi-Pure, X-nitrate, or whatever else you decide on using,
including resins.

  Use one or more canister filters in addition to your
trickle filter. Fill them with any of the above compounds, or use
them for additional biological filtration by filling them with
plastic filtering media. The efficiency of Bio-Techs, used in
submersed form, is 65 percent of their efficiency in
non-submersed form. A large difference, but still quite of a lot
of extra biological filtration ability.

   If you are using ozone, make sure none of it is
finding its way into the back chamber (biological chamber) of
your filter. Ozone will destroy some, or all, of the bacteria,
and will greatly reduce the efficiency of your filter in the
process.

   Set up a reverse osmosis drip system, running the
output of the unit directly into your sump. Use a very small
unit, and do not let it run continuously. Use it to change water
very slowly, and make up for evaporation at the same time. If you
let it run for long periods of time, the water level in the sump
will rise, and could overflow, unless of course you have a drain
piped in. This is done by running a hose attached to a tank
fitting, placed at the appropriate height, from the sump to a
drain, or to a sink that is lower than the sump (e.g. in a
cellar).

   If you do not have a drain, use a power head coupled to a
float switch that kicks the pump on, when the level in the sump
rises above a certain height. That water can then be pumped to a
vat or sink, or wherever you can dispose of it. Always watch your
salinity carefully when you are doing this, because you are
adding fresh water, which will make your salinity go down slowly,
but down nevertheless. Make up for this change in salinity, or
specific gravity, at appropriate times.

   There are, I am sure, many other tried methods. If you
have one that really worked for you, I would like to hear from
you at Marine Reef, the Newsletter. We will compensate you for
your contribution if it is published in the newsletter.

    In-Line Cartridge Canisters :

These canisters, which can often be bought at
do-it-yourself type hardware stores, and carry brand names such
as Cuno, Water Kleen, AquaPure, etc. can be piped in-line with
the water flow.

Some even have a by-pass assembly built-in to the unit,
e.g. the units sold by Thiel-Aqua-Tech, making changing the
cartridge very easy, because it does not require you to stop the
system at all. Alternatively you can pipe-in the by-pass
yourself.

Many types of cartridges for such filters are available :

    to remove rust

    to remove fine particulate matter, rated in micron
    ratings

    filled with activated carbon

    filled with a mixture of compounds to purify the
    water

Keep in mind, when installing such in-line canisters,
that they all put a lot of back pressure on your pump(s). This
will reduce the water flow through the filters and through the
tank.

Micron ratings go in various sequences, usually <1
micron, <1<5 micron, 5 micron, 25, 50 etc. microns. You should
also know the difference between absolute and nomimal ratings.
Absolute means no particles of the size given, or larger, can go
through the cartridge. Nominal means "most" of the particle of
the size given will get trapped, but some will get through.
Nominal rated cartridges are good enough for our purposes, and 25
or 50 micron rated ones should take out most of the free floating
material that you may want to remove. Do not go too low in the
rating, because you do not want to filter out all of the living
organisms, indeed filter feeders need them for survival.

Moreover, the finer filtering the cartridge performs, the
sooner it will plug, and the sooner it will need replacing. That
can add up to quite a few dollars, if you have to do so too
frequently.

Two types of such cartridges deserve special mention,
they are manufactured and sold by Poly-Bio-Marine (through their
distributors) : the PMA and PSM types, the former performing
molecular absorption filtration, and the second one sub-micronic
filtration.

The one of most interest, in my opinion, is the PMA unit.
They are specially tooled to be able to hold a number of disks,
of Poly Filter material in disc form. Because of the way they are
constructed, all the water has to go through the disks, before it
can actually re-enter the main water stream.

Because Poly Filters are so highly efficient, and because
these canisters are easy to install and service, we highly
recommend them. In fact, I personally use them on all systems I
install, and of course on my own show aquarium.

PSM canisters should not be used in continuous operation
form in Reef tanks, because they remove all the material that
filter feeders need. You should pipe them in so you can run them
for a few hours, and then by-pass them without having to stop the
system.

See the diagram on the next page for one method of piping
in such a by-pass. The first canister shown could be any type,
and is not required. It is shown here, because many Hobbyists use
both PMA and PSM canisters in-line, one after the other. The
first one should be the micronic, and the second one the
molecular absorption one. The first one removes very fine
particulate matter, and the second one acts as an extremely
efficient chemical filter.

Remember to take the PSM cartridge off after you by-pass
it, otherwise the water in the canisters will go anaerobic, and
the next time you try to use it, you will push all that anaerobic
material in the tank. Such is very dangerous for your
invertebrates, and even for the fish you keep. With a properly
set up by-pass, this problem  does not arise. Just unscrew the
bottom of the canister, rinse the bags inside, empty the canister
and replace it.

The above diagram shows that you can isolate one or both
canisters, meaning by-pass just the first one, or both, by
switching the valves around. Under normal circumstances you would
run the first canister, e.g. with a cartridge filter of, for
instance, 25 or 50 microns, or a PSM module, and the second one
with Poly Filters, X-nitrate, or some similar product.

Remember the remark about emptying the micron filter when
it is not in use, to prevent the formation of anaerobic
by-products. If you don't, the next time you place it back in
line (use it) all these anaerobic compounds will end up in your
system, and will create a great deal of stress on the tank life.
It will greatly reduce your redox potential, reduce dissolved
oxygen levels, and may even kill off some of the tank life.

   Automatic Float Switches

We already covered float switches earlier. There is,
however, one switch on the market that is both very reliable
(over 100.000 operations) compact, and inexpensive that you may
want to consider for your system : the Thiel-Aqua-Tech  Super
Float, which at the time of this writing retailed for $ 76.00.

It comes in a molded housing that you place into the
sump, at the appropriate height, and connect into the pump
wiring, as shown in the diagram. It can be used for inductive
loads (e.g. pumps in our case) up to 5 amps, 110 volts. It should
be affixed to the bottom of the sump, or vat, by means of a
suction cup, or a little aquarium silicone. If it needs to be
placed off the bottom, on a ledge of some sorts, because of the
amount of water you keep in the sump, affix it to that ledge.

Note the following :

   Only two wires come out off the Super float molded
box. Some switches may have more wires, find out from the
supplier which ones you should use to control the low, or high,
triggering operation.

   Only one of three wires that make up the pump lead
that ends with a plug is used. Check the diagram carefully before
wiring the switch in. The pump lead is the cord that comes off
your pump.

   This is called a splice, and where the connections are
made, electrical tape has to be used to insulate the connections
and make them water tight.

   Never attempt to wire the Super float, or any other
float switch while the pump is plugged in ! You will get an
electrical shock.

   Do not submerse the part of the electrical cord where
you have made the splices, and covered them with electrical tape.

   If you acquire the Super Float, do not operate it with
pumps that draw more than 5 Amps. Check for the rating of other
switches with whomever you bought it from. Operating a device at
more than the rated amperage will ruin the device, in a short
period of time, and can in some cases cause serious electrical
shock.

   The Super float, or any other float switch for that
matter, must be placed in the sump, at the appropriate height.
The installation of switches can sometimes be cumbersome, e.g.
the orange german one available on the market. The Super Float is
merely placed in the sump, on a base, if necessary, to adjust the
height in deeper type sumps.

   Incidentally, 100 000 minimum guaranteed operations of
the switch, corresponds to about 5 years of continuous usage,
with the switch going on and off about 55 times a day. That is
most unlikely, on average, switches operate perhaps 10 to 15
times a day, if that much, greatly extending the guaranteed life
of the switch.

   Any pump can be operated with a float switch,
including a power head type pump. Anything that works with
electricity, in fact, can be operated with a float switch,
providing , of course, that it makes sense to do so. Besides a
pump, you may want to operate a solenoid that controls some
outside device with such a switch. This is, however, not part of
the basic system we are looking at in this book.

   Converting from an Undergravel to a Reef System

While on the subject of biological filtration, let's
review how one can convert a traditional undergravel system to a
Reef Tank. Many Hobbyists, and you may be among them, already
have a tank set up, either a fish-only, or perhaps even an
aquarium with a mixture of fish and invertebrates, installed with
undergravel plates, and perhaps one or several canister filters
as well. Transforming such a system into a more modern one,
using a trickle filter, is quite uncomplicated.

There are basically two major approaches :

   Maintain the undergravel system, while adding a
   trickle filter,

   Do away with the undergravel filter altogether.

You may elect to keep the canister filters, yet fill them
with different compounds, e.g. chemical filters, as we shall see
later.

Both are viable approaches, but the second one is the
better one of the two, because it takes a potential area of low
oxygen and pollution out of the system, while improving the
overall quality of the biological filtration considerably. You
may want to start with method one, let the tank run for a while
in that fashion, and convert to a full Reef system at some later
date.

    Maintaining the Undergravel :

   Design the system you would like to end up with. Lay
it out on paper, so you know what kind of parts and components
you will need to acquire. Make sure all the parts will fit inside
the aquarium cabinet. Measure carefully !

   Obtain an appropriately sized trickle filter, taking
   the recommendations made earlier in this book into account.

   Select an internal medium. Use one of the many
   plastic/ polyethylene ones now offered for sale. Some Hobbyists
   use plastic haircurlers. This may work, providing you use the
   clear ones that cannot leach a dye into the water. It would be
   safer however if you used a more traditional type of biological
   medium, e.g. Techs, Blocks, Spheres, Balls, Rings, Cubes, etc.
   There are plenty of them around.

   Determine the quantity you need, based on the
   suggestions made in this, and other books.

   Obtain a surface skimming syphon, preferably one that
   will re-start automatically, and keep its prime, even if the
   power and/or pump fails. This will make it unnecessary  for you
   to re-prime it.

   If you do not have one, buy a pump, and if you can
   budget for it, a float switch as well. It protects the pump and
   the system itself.

   If you are not getting a protein skimmer right now,
   start thinking about it, because you will need it to maintain
   adequate water chemistry parameters. In light of this, you may
   want to get a filter with the right sized, ozone safe and
   resistent protein skimmer built-in.

   Flexible vinyl, or acrylic, hose piping is an
   excellent way to go, and requires less time and expertise to
   install. Clamp all flexible hose connections to prevent slippage
   due to pressure, and leakage.

   Install the filter and all other components of the
   system.

   Do not forget to blow air into the biological chamber
   of your trickle filter. This is important for the potency
   (meaning how effectively it will perform) of your biological
   filter. Use a good, strong air pump. We suggest a Whisper 1000 or
   a pump with an equivalent output.

   Fill the sump of the trickle filter with salt water,
   and start the pump, after priming the syphon of the surface
   skimmer.

   Check all connections to ensure that you have no
   leaks. If you do, fix them now. Usually just tightening a clamp
   will do the job.

   If need be, adjust the water level in the sump .
   Sometimes the pump will push up water so fast, that the sump
   water level becomes a little too low, and air gets sucked into
   the pump. If you have a float switch installed, the pump will
   shut off before that happens, providing you have set the float to
   kick on and off at the right level. If not, now is the time to
   adjust it, so it triggers at the correct level.

   We have not mentioned the undergravel yet, because we
   do not want you to change anything to it, at least not yet.

   Let the system run on both the undergravel, and the
trickle filter, for one week to ten days. Because of the
biological activity going on, and bacteria populating your new
trickle filter, acidity is produced. This will affect both your
carbonate hardness and the pH of the water. You should not worry
about this, except if the pH goes down to dangerous levels e.g.
7.6 - 7.7. If this happens, you should add a carbonate hardness
generator to your tank's water, preferably a liquid one, or a
powdered, or tablet form, that does not make the protein skimmer
foam excessively and starts overflowing.

   Since your undergravel is still operating as it was
before you added the trickle filter, water quality, as far as
ammonia and nitrite are concerned, should not be a problem. In
fact, if you had any before, you should'nt now. You have a better
filter!

   After 7 to 10 days  you need to give your undergravel
filter a serious cleaning. In order not to disturb the total
undergravel biological filter, however, clean only 50 percent of
the filter (e.g. one side of the tank, or just one plate if you
have several).

   After cleaning the undergravel filter, perform a 15
percent water change, and another 10 percent about 6 hours later.

   Now wait another 7 to 10 days, and clean the other
half of the undergravel filter. Again, perform a 15 percent water
change after the cleaning is completed, and a 10 percent water
change approximately 6 hours later.

   Next, reduce the flow of water going through the
undergravel filter. Do not stop the flow through the undergravel
completely ! You would be creating an anaerobic environment very
quickly if you did. Just slow the flow down to a minimum, much
lower than what you had before. The reason for this, is that at a
lower flow, detritus will not be pulled into the undergravel so
easily, and no oxygen, or at least much less, will be taken out
of the water by detritus breaking down in the under-gravel
filtration system. Your tanks water will, as a result, have a
higher dissolved oxygen and redox potential level.

   Check for ammonia and nitrite throughout the
switch-over period. It is unlikely that any significant amounts
will be found, although you may detect more of it than you
normally would for a few days, especially right after you clean
the undergravel filter.

   Your switch-over is completed, and you now have a
modern reef system. Clean your undergravel every 2 months or so,
to remove detritus that may have accumulated.

   Converting and Removing the undergravel :

In the interest of maximizing water quality, it is much
better, filtration-wise, when converting to a modern Reef System,
to remove the undergravel filter completely. This may not be as
practical as the previous solution, but it is definitely more
efficient, and to the benefit of all tank lifeforms, especially
the more sensitive corals and invertebrates.

Because of the nature of dolomite, or crushed coral, and
the usual size in which it is sold as undergravel filter
material, it easily traps detritus as water is pulled through it
by the up-lift tubes and by, power heads. In fact more so with
the latter.

Many Hobbyists will remark that reverse flow is a much
better way of operating such filters, because the water can then
easily be pre-filtered before it is pushed back through the
filter bed itself, and into the aquarium. That is of course
entirely correct, but detritus still gets trapped. It is just of
a smaller size, and the clogging process will take longer to
occur, but occur it will. Just stir up an old undergravel filter
bed, and you will agree with me that the material that you can
see coming out of the filter bed, cannot really be conducive to
the higher water qualities that we are looking for in a Reef
aquarium.

We are not saying that undergravel filters do not work,
they do of course. If they did'nt, the hobby would not be where
it is now. What we are saying is that you can do better, improve
the water quality significantly, by removing the undergravel and
switching over to a trickle filter as the sole biological filter
of the tank.

The steps involved in doing this are similar to the ones
described in the previous section, up to the point where we
recommend that you clean half of the undergravel bed thorougly.
Instead of waiting 7 to 10 days, wait 14 days, meaning let both
the undergravel and the trickle filter run the tank for 2 weeks,
then remove half of the undergravel (or in larger tanks remove
one third) including the plates.

This is labor intensive work for which you must plan, as
it may take quite a while to do. After the plate, the crushed
coral and dolomite are removed, perform a 20 percent water
change. Wait about 6 hours, then perform another 10 percent water
change. Since you may have two (or more) plates to remove this
whole process may take up to 30 days to complete. Change plates
at 10 day intervals, and perform water changes each time, as
indicated.

The easiest way to remove the dolomite, or crushed coral,
is to syphon it out with a large diameter hose. This will reduce
the amount of material (detritus and mulm) getting into the
water. You will be removing water at the same time, which you
need to do anyway, because of the recommended water changes.
Watch the pH, and add a carbonate hardness generating fluid (or
tablets, powders without binders), if it drops too low. Beware of
products that contain nothing else but baking soda !

   Remarks on the Conversion Process :

    Because in both types of conversions the existing
undergravel, and the new trickle  filter, are running at the same
time, the seeding of the new filter with bacteria is automatic,
and the cycling happens without the Hobbyist noticing it. Indeed,
you already had a lot of bacteria in the system. They are being
transferred to a different medium.

    As long as the existing undergravel filter was able
to keep ammonia and nitrite down to zero, no increase will be
noticed in the first 7-14 days, while both filters are running
together.

    After cleaning the undergravel (in one scenario) and
removing part of it (in the other), a small amount of ammonia
and nitrite may be present for a few days. The amount will,
however, not be high and stress on the fish will be minimal.
There will be some degree of stress that the animals will have to
cope with, that is unavoidable, indeed, you are making changes.

    Do not add any fish or invertebrates whatsoever
during the conversion process! None whatsoever.

    Clean all mechanical filters before you start the
conversion.

    To alleviate stress on the tank life change your Poly
Filters if you are using them already. If you are not, we suggest
that you add 1 Filter per 25 gallons of water in the system. To
find that number, add the volume of water that is in the sump, to
the gallon content of the tank. Multiply that by 90 percent (to
account for displacement by rocks etc..) and use that number.

    Remember that the water going to the trickle filter
needs to be pre-filtered. If you don't do so, you will have to
clean the drip plate of the filter regularly. Good quality syphon
surface skimmers will have such a pre-filter built-in.

    If you are using a spray bar, which we recommended
you did'nt, pre-filtering is even more important.

    The recommended water changes that go in hand with
the cleaning of the undergravel filter, and removing the plates,
are very important. They are meant to remove the noxious toxins
that result from stirring up the material used on the filter
plates, from the water. Not doing so may lead to a lot of
problems.

    In the first type of conversion, where the
undergravel filter is not removed, you must clean the undergravel
filtering medium very thoroughly, to remove any material that can
cause oxygen depletion, anaerobic activity, plugging of the
crushed coral or dolomite, etc.

    In the second type of conversion, where the
undergravel is removed in several stages (at least two), it is
very important that the medium on the filter plates be syphoned
out. This will prevent the detritus in the crushed coral, or
dolomite, from mixing with the tank   water. Some of it will, but
you must try to minimize that mixing as much as possible, because
of the toxins it also contains.

    Remember not to turn the undergravel filtering system
pumps (air or  power heads) completely off. Reduce the
throughput, but do not shut it off completely. If you do, the
layer of water underneath the plates, and the material on the
plates, will quickly produce anaerobic by-products. This may kill
off everything you keep in the tank. Many Hobbyists have made
that mistake before you, and have wondered why, even though they
added a trickle filter, they could not raise the water quality.

    Do not rush the conversion. Take your time. Follow
the suggested timeframe. Your fish and invertebrates will benefit
from it.

    If you were using canister filters in conjunction
with your undergravel filter, you can certainly continue to use
them with the new filtration you installed. It seems, however,
that they should then be used for other purposes : additional
mechanical filtration (clean them at least once a week), chemical
filtration (see next section), special compounds e.g. to remove
nitrate from the water, etc.Run them, taking water from the sump,
and returning it to the sump.

    Because of the changes you are making to the
filtration, initially, changes to the water chemistry will affect
the redox potential; it will go down, but come back up after a
few days, to a week maximum.

    Dissolved oxygen and carbon dioxide levels will also
be affected, but not to the point where you have to be concerned
about it.

Changing over to trickle filtration is a positive move.
It will take time to perform, but it will greatly benefit your
system in the short, and long run. It definitely is a positive
step for the water quality, and ultimately for how your tank will
look some weeks down the road.

[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]
SMALL REEF AQUARIUM BASICS
    
Chemical Filtration

    General Remarks

This is probably the least understood form of filtration that is required 
in fish-only as well as in Reef tanks, even more so in the latter.

Mechanical filtration removes particulate matter of varying sizes; 
biological filtration removes ammonia and nitrite by means of bacterial 
processes, and converts it to nitrate; chemical filtration removes yet 
other types of compounds, some of which are not normally removed by the 
former, some of which are not removed by protein skimmers either (see 
next section).

The best known form of chemical filtration is activated carbon, others 
include molecular absorption filters (e.g. Poly filters), resins (e.g. 
HyperSorb), and special compounds meant to selectively remove certain 
elements from the water.

What kind of compounds are we talking about?  Besides the undesirable 
elements already mentioned, e.g. free floating material, nitrogen breakdown 
intermediates, seawater absorbs many noxious elements from the surrounding 
air (e.g. nicotine, tar, fumes, perfume essence, volatile organic compounds 
etc..), chemicals that, when they accumulate, can stress the tank life 
considerably. 

Besides these, many chemical compounds are formed in the aquarium and are 
not removed by the filters already mentioned. Included in this category 
are, for example, yellowing matter (gilvin), organic acids, heavy metals 
that may come in with the tap water, pesticides in very small quantities 
(ppb's), etc.

The principles of chemical filtration are based on molecule adsorption, and 
on ion affinity, allowing certain compounds that we add to the filtration 
system to remove unwanted elements very efficiently. Because we do not 
"see" the filter at work, certainly not as much as we can determine what a 
mechanical filter is doing for example, these type of filters can be 
extremely beneficial, especially if the material used is replaced on a 
regular basis.

I conducted many experiments along the lines of chemical filtration, using 
an assortment of chemical filtering materials. All work, some much better 
than others. Two types in particular are very familiar to most hobbyists : 
activated carbon and Poly Filters. Resins and other compounds are used less 
frequently, except perhaps for the "X-nitrate" compound from 
Thiel-Aqua-Tech, which is very specific for Nitrate ions, and can lower the 
total NO3 in seawater to the 2-5 ppm range in a matter of 7 to 10 days. 
Unlike carbon, this product cannot be regenerated. Then again, regenerating 
carbon is not recommended anyway, as Hobbyists do not really have the 
equipment to do so efficiently.

    Activated Carbon

Many types of carbon are sold in Pet Stores. Unfortunately the Hobbyist has 
no way of knowing which ones are good, bad or better. Some brands are 
merely charcoal (usually shiny) and are very ineffective at removing 
noxious compounds. You should definitely avoid them in Reef Aquariums.

Other types are "activated", a process that substantially increases the 
porosity of the carbon, and as a result greatly increases the total active 
surface area, usually depicted in drawings as an intricate path of holes, 
and channels in the carbon, allowing it to be much more effective at 
adsorbing compounds that need to be removed from the Reef tank's water. The 
amount of pores and channels is what is of interest to us.

Activated carbon has a maximum adsorption capacity, which is the reason 
that it should be replaced from time to time. How frequently is hard to 
determine, because it is dependent on the quality of the water that is 
flowed through the carbon. Note that we said flowed "through" and not over. 
Your activated carbon will work much better if water is actually forced to 
go through the amount used, rather than just flowed by, and over it. More 
contact between the activated carbon and the water obviously results in a 
more efficient cleansing process. 

One problem that frequently occurs in saltwater tanks with a heavy organic 
load, is that the outside of the carbon becomes quickly coated with organic 
matter and slime, preventing further uptake and adsorption of unwanted 
compounds from the water.

How much carbon you should use, if you decide on this method of chemical 
filtration, is open to much debate. Some advocate small quantities of only 
a few ounces per 50 gallons of water in the system, to quantities that are 
7 to 8 times larger.

Our recommendation is that if you use a good quality brand, you can safely 
follow the manufacturers' recommendations. Perhaps the most frequently 
recommended type is Chemi Pure from Dick Boyd Enterprises. It has been 
around for along time, and has obviously proven itself to many Hobbyists. 
We use our own Tech-Coconut-Shell brand.

Activated carbon is used to remove DOC (dissolved organic compounds), 
yellowing matter, heavy metals  e.g. copper and iron (to some extent), 
airborne pollution, trace elements, intermediate protein breakdown 
products, and so on. Quite an amount of elements indeed. It is, therefore, 
an efficient chemical filtration material.

Since it removes trace elements as well, it is important to perform water 
changes from time to time (4 to 5 percent a week is my usual 
recommendation) to replenish such needed elements, or add one of the 
commercially available trace element mixes  (e.g. Reef Elements from T-A-T, 
CoraLife, HW Trace Elements, Tropic Marine, etc.)

When using activated carbon, keep the following in mind :
 
   Smaller granules, or pellets, will do a much better job, because of a 
   higher total surface area, meaning greater porosity.
 
   If only small amounts of activated carbon are used, you will need to 
   replace it often, perhaps as much as every 2 to 3 weeks.
 
   Rinse all activated carbon before using it, to remove fine material and 
   dust, that will otherwise end up in the tank and on the rocks. This black 
   dust is hard to remove, and makes the tank look very unsightly, besides 
   being noxious to fish and invertebrates.
 
   Ensure that a good "through" flow takes place. Do so by placing the 
   carbon in a compartment of the trickle filter through which all the water 
   has to flow, or better still :

    place the activated carbon between layers of polyester floss filtering 
    material, in a good quality canister filter. The new Eheim 2200 series 
    canisters are highly recommended as they offer good flow and move quite a 
    bit of water. Magnum and Fluval are other choices.
    
    Because good quality activated carbon is expensive, it is important to 
pre-filter the water that goes through the canister, or the compartment in 
the filter, to prevent the carbon from becoming coated with fine 
particulate matter, and acting as a mechanical rather than chemical filter. 
This ruins the efficiency of the activated carbon fast.
 
   Test the carbon that you plan to use for leaching of phosphate. Soak 
some carbon in a little tap water, or aquarium water, wait about 6 hours. 
Now take a sample of the water and test it for phosphate content. You will 
be surprised to find the number of brands that actually leach phosphate 
into the aquarium. Such types of activated carbon are of course totally 
unacceptable for use in Reef Aquariums. J. Asero (1989) evaluated many 
types of carbon, and found only few that did not leach carbon in the water. 
For a more detailed review we refer you to Marine Reef, the newsletter, 
Volume 2 Number 20.

    Some carbons may also leach sulfate, and metals, into your water. Make 
sure you buy top quality carbon and you will avoid these problems. Coconut 
shell carbon is probably the best, but also the most expensive. In a Small 
Reef you should not take any chances. 

    Make sure that you change the activated carbon regularly. Many types of 
carbon are known to leach some of the matter they first adsorb back into 
the water, once they have exhausted their ability to remove matter from the 
water. Chemically speaking what may be at work here, is ion displacement , 
with the ones for which the carbon has more affinity displacing ions for 
which there exists lesser affinity. The displacement results in these ions 
ending back up in the water (Thiel, 1989).

    Exhausted activated carbon will soon start acting as a small biological 
filter and will also, as time goes by, act as a mechanical filter. This is 
not desirable because you have no control over what compounds leach back 
into the water. Spent activated carbon should, therefore, be removed and 
replaced. You can tell whether your carbon is still "working" (removing 
compounds from the water) by checking whether your water is yellowing. Make 
a very faint yellow mark on a small piece of white plastic, submerse it and 
look at it from about 12 to 18 inches away. If you cannot see the 
difference between the very faint yellow and the white, your water is 
obviously slightly yellow, and your carbon needs changing. 

    Some lesser quality types of activated carbon may alter the pH too 
much. Usually they will raise it. Sometimes considerably. Acid washed 
carbon will not.

    Fresh activated carbon will lower dissolved oxygen levels for a short 
period of time, and may as a result lower your redox potential as well. 
This is however short lived.

    Soak new carbon in warm water to remove gas bubbles trapped in the 
pores. This will improve the efficiency of the carbon substantially.

    When in doubt about the freshness of your carbon, do not use it, or if 
it is in your filter already, change it.

    You may also want to filter the air going into your trickle filter by 
running it through a small column of carbon first. This will remove 
airborne pollutants. An old air dryer that you are not using can be filled 
with a good brand of carbon and place in-line with the air flow. Some units 
are commercially available (e.g. T-A-T).

    Carbon removes organics from the water, to some extent anyway, but does 
not do away with the need to use a properly sized protein skimmer on your 
system as well. All you get is some degree of polishing of the water, not 
total removal. Refer to the section on protein skimmers for more details.

    Pulverized activated carbon offers the largest surface area of all 
carbons. It is however not as easy to use, and needs to be set up with a 
diatom filter, or low micron filter, at the same time. This will result in 
the need to change the carbon frequently, as diatom and low micron 
cartridges, or special very low mesh bags, will of course plug up faster, 
as they trap very small particulate matter as well.

    Of all the activated carbon types I have used myself, I prefer a 
granule, about one eighth to three sixteenths of an inch in diameter. The 
granules must be "dull", not shiny! Of course, that is the kind my company 
sells, as it is the one that I have found works best.

    Do not overlook the need to add carbon to the system if you are using 
ozone. Best is to flow the water coming out of the skimmer over a little 
activated carbon, before it can re-enter the main water stream back to the 
aquarium. Trickle filters that have compartments built-in that allow you to 
do so are, therefore, to be preferred.

    Although at some time I was convinced, based on experiments, that in 
the case of activated carbon "more was better", I have since changed my 
recommendations. I now recommend approximately one half pound of activated 
carbon of very high quality per 75 gallons of water, with the stipulation 
that the activated carbon must be changed every 5 weeks, regardless of how 
well the tank may be doing. This will ensure that the carbon is always 
removing pollutants from the tank.

    You can safely mix several forms of chemical filtration. For example, 
you can use activated carbon and resins, or activated carbon and molecular 
absorption pads (Poly Filters) or disks (PMA discs from Poly-Bio Marine) . 
The latter of the two is the better.

It may appear to you, that selecting carbon has become a little more 
complicated than it used to be. Indeed it is. Unfortunately the better 
qualities we refer to are hard to come by. Knowing all the problems 
associated with activated carbon, my own company obviously sells only top 
quality coconut shell, acid washed to ensure a stable pH.

   Deionizing Resins :

Before deciding to invest in a D.I. unit, read this section several times, 
especially the parts dealing with regenerating the resins. The latter is 
not simple, and can be dangerous.

Even though I have looked for resins that perform consistently well in a 
salt water environment, I have not yet been able to find such a resin. What 
I am looking for is a resin that is a very specific though.

Some resins can, of course, be used, but they exhaust their adsorption 
ability very quickly and are, therefore, in my mind, a waste of money. What 
happens is that the exterior of the resin becomes coated with larger ions 
(e.g. sodium and chloride) and a protein surface coating from the organic 
load of the water. As a result no other ions can migrate to the inner 
structure of the resin, where the larger part of the adsorption takes 
place. This, then, results in a very very poor utilization of an expensive 
medium.

If you are trying to remove nitrates, phosphates, and heavy metals from the 
tank itself, disregard using deionizing resins until such time as much more 
efficient types become available. Beware, of anyone trying to sell you a 
resin that will do all sorts of wonders for your tank. So far I have not 
found one, but some will appear, hopefully soon. 

Resins should be used to treat the water to which you will be adding salt, 
before you actually add the salt, to remove impurities, nitrates, 
phosphates, and so on. Such treated water can then be safely added to the 
tank. In some cases it will be necessary to aerate the water before using 
it, because the de-ionized water will be very low in dissolved oxygen. It 
is a good idea to test for D.O. the first time you use whatever resin you 
may have acquired. This will tell you whether to expect low D.O. in the 
effluent water or not, allowing you to determine whether or not to aerate 
it first.

Many resins that will "purify" tap and well water are available. The key is 
to get the kind that will do exactly what you are looking for, can be 
easily recharged, or regenerated, using chemicals that can easily be 
obtained, and can be used without undue precautions.

There are basically 2 types of resins available to the Hobbyist:
-->  Anion resins (pronounced an__ion)
-->  Cation resins (pronounced cat__ion)

Resins are sold as monobed (one resin) or mixes (e.g. 2 resins). To confuse 
you a little, the word monobed is sometimes used to refer to a single 
deionizing column (device), that may contain a mixture of 2 resins (monobed 
= 1 bed of resins).

In double columns, the ones where 2 resins are used, and are kept 
separated, the cation exchange resin must be used first. The water flows 
first through the cation column and then from the cation resin to the anion 
resin. Flow rates recommended vary greatly; the best results are usually 
obtained with flow rates of 1-2 gallons of water per minute, per cubic foot 
of resin. Since most Hobbyists' deionizers only contain about 1/6 of a 
cubic foot, the flow rates should be adjusted accordingly to about 10 to 20 
gallons per hour. If your unit contains  even less, e.g. only 1/8 of a 
cubic foot, the recommended flow rate is 7 GPH. Very slow indeed.

Although recirculating the water through the resin will work, most 
manufacturers recommend "single pass" operations. This means that the water 
to be treated is flowed only once through the resin, and as slowly as 
possible. This is also what I now recommend you do.

Slow flow rates, such as the ones mentioned, are best obtained by gravity 
feed, without the use of a pump. Just let the water flow slowly through the 
resin. In two column units, first through the cation and then through the 
anion. In single mixed bed resin units the principle is the same, let the 
water flow slowly from the top of the column to the bottom, in a single 
pass treatment fashion.

The useful life of resins is theoretically indefinite, because, once 
exhausted, the resins can be recharged, regenerated, and used again as new. 
Practically, this is however not the case. Some resin will be lost, e.g. 
when regenerating, and you will need to add resin to the unit at some 
point. Not a lot, but you may find that after several months (6-7) you may 
need to add a pound or so.

Hobbyists never have a problem installing a de-ionizing unit. Problems come 
about when regeneration time comes around. Here are two ways to approach 
this matter, depending on whether you are using a single or double column 
unit (remember : regenerating resins can be dangerous if you are not 
familiar with the use of the chemicals needed):

   Double de-ionizing Units :

These units consist of two columns, one filled with a cation exchanger and 
one filled with an anion exchanger resin. Each of the columns requires a 
different recharging method.
 
      Cation Resin Exchanger :

Prepare a solution of 4 percent acid content. For every pound of resin you 
have, you will need about 2 gallons of water to treat the resin (water that 
has been treated with acid). To make a 4 percent acid solution you will 
need HCl or H2SO4, not something you usually have standing around, unless 
you are a chemist, a doctor, etc..

Swimming Pool places, and some hardware stores, sell a product called 
"Muriatic acid". This is usually a 32 percent or a 20 percent solution of 
HCl (hydrochloric acid). It will say so on the bottle. Muriatic acid can be 
further diluted to obtain a 4 percent HCl solution, that you can then run 
slowly through your de-ionizing cation exchange resin. Lower HCl solutions, 
e.g. 10 % are sold too. They should be preferred as they are less dangerous 
to use. 

Remember to use great caution when working with  Muriatic acid. Acids can 
burn your skin, damage clothing, furniture, carpets etc... Read the 
instructions very carefully, and if you are not sure about what to do, 
don't do anything. Ask someone who knows. If you spill any on yourself, you 
must wash it off immediately. Never add water to the concentrated acid. You 
must add acid to water and very slowly. Stay away from sulfuric acid, it is 
a much more dangerous acid chemical.

For example : you buy a 32 percent HCl Muriatic acid. The bottle holds half 
a gallon. If you now add this half gallon of Muriatic acid very slowly to 
half a gallon of water, you have a 16 percent solution, and a total of one 
gallon of water. Adding this to a gallon of water will give you a total of 
2 gallons, and an 8 percent solution. Adding this to another 2 gallons of 
water will give you a total of 4 gallons and a 4 percent solution of HCl. 
Remember HCl is a very acid chemical and can easily burn your skin, 
carpets, clothes, furniture....Use care and good judgement, and keep all 
chemicals away from children.

Four gallons is enough to treat 2 pounds of resin. If you have more resin, 
you will need to make more 4 percent solution. If you had, for instance, 5 
pounds of resin, you will need to make 2.5 times the above quantity.
Another example : You buy a one gallon bottle of 20 percent HCl solution 
Muriatic acid. Add this to one gallon of water and you have a 10 percent 
solution and 2 gallons total. Add this to 2 gallons of water and you have 4 
gallons total of a 5 percent solution.To go from a 5 % solution to a 4 %, 
you need to reduce the concentration by 20 % because 80 % of 5 = 4. 
 
This may seem complicated at first, but it is'nt really. Granted, you may 
have to do some calculations, but as long as you know the concentration of 
the muriatic acid, you should not find it difficult to get to the right 
dilution quickly.

Remember that you are working with an acid, and that you should follow the 
precautionary instructions that come with the Muriatic Acid you bought. 
Especially, keep it away from children. If you do not know how to work with 
such chemicals stay away from them. Use a different method to purify the 
water. We highly recommend molecular absorption (see the section on water 
purification).

Once you have prepared the necessary quantity of treatment water, run it 
through your de-ionizer slowly, 0.5 gallons per minute is plenty (1 30 
gallons per hour). Collect the outflowing water/acid mix, and dispose of it 
safely. Do not store it. Get rid of it safely right away. You cannot use it 
a second time ! Best is to add it to a bucket full or two of more water to 
dilute it even further.

After you have treated the resin, you must flush it with distilled, or 
previoulsy deionized, water to remove the acid form the column. If you 
don't do this, the first couple of gallons coming out of the unit will be 
very acid, and will not be usable  unless you first neutralize the acidity 
with e.g. Calcium or Sodium carbonates or bicarbonates. Flushing is usually 
much easier and is, therefore, to be recommended.

     Anion Exchange Resin :

Anion exchange resins must be regenerated separately from the cation 
resins, and this time using a 4 percent base solution (with a high pH).
You must now prepare a 4 percent solution based on the method already 
described, using Sodium Hydroxide. This can usually be obtained from 
hardware stores as caustic soda, as it is also used to unclog clogged drain 
pipes of sinks.

Because this is a stronger chemical, please follow the directions on the 
can or bottle or container very carefully. You are not doing anything 
dangerous, but you must be careful, that's all. Keep the mixture and the 
chemicals away from children. Dispose of the effluent safely by diluting it 
even further.

Run the  mixture slowly through the resin, again at about 30 gallons per 
hour, and this time use 3 gallons per pound of resin you have. Dispose of 
the effluent safely and immediately. Do not store it. You can not reuse 
it. Flush the unit slowly to remove all remaining caustic material, lest 
the pH of the water you will treat will be too high.

When should you regenerate ? 

- when the resin is no longer removing all the elements you want to remove, 
e.g. nitrates and phosphates.

- when total dissolved solids measure more than 30-40 ppm. Small, 
inexpensive, handheld units measuring TDS are advertised in hobby 
magazines, or can be bought from scientific supply houses.

       Single de-ionizing Units :

Single column de-ionizers, using a mixed bed (2 resins), are regenerated in 
exactly the same manner as double units, but first the resins need to be 
separated.

First you must remove the resin from the container. Place it in a larger 
one, at the bottom of which you have placed one or two air stones. Place 
filter floss over the resin, as well as a rather tight fitting lid with 
some holes in it, for the water to come through. 

Now pump water slowly into that vat, from the bottom, and blow air slowly 
as well at the same time. The action of the water and of the air will make 
the lighter anion resin migrate to the top, and the heavier cation 
exchanger will go to the bottom. In the middle a small band of mixed resin 
will remain. Old columnar protein skimmers make ideal containers to do 
this, as long as you pump the water in through the original "outflow" of 
the skimmer, and let the water come out where it would normally have gone 
in when the unit is run as a  skimmer (you are in essence reversing the in 
and out).

Remove the anion resin and treat as indicated in the previous section. 
Remove the mixed resin layer and dispose of it. It cannot be separated 
easily, and can not be recharged. Since mixed bed exchangers contain equal 
amounts of both types of resin, the mixed layer is in the middle. Remove 
the cation exchange resin, and treat as explained in the previous section.

General Remarks on Resins :

   Never deionize water to which salt has been added already.

   The better the water you start with, the longer your resin will 
   obviously last.
   
   Some Hobbyist first use reverse osmosis, then deionize.

   Regenerate frequently. The effluent water will always be better.
   In double units always run water through the Cation resin first.

   Flowing water through activated carbon before D.I. extends the resin 
   life.

   Flowing water through carbon after D.I. "may" purify the water more and 
   better. It is better to put it before the D.I. unit.

   Flowing water thru Poly Filters after D.I. will purify the water even 
   more.

   Flowing water thru Poly Filters before D.I.  will extend the resin life.

   Remove all water from D.I. units that are not in use, and/or stored.

   Turn units not in use upside down in a bucket or so.

   If water remains in a unit when not in use, it will stagnate and smell 
   because of anaerobics.

   Before each session of D.I. flush the unit with some water.

   If the outcoming water smells at first, flush it until it doesn't 
   anymore. Or regenerate the resins.

   Check the D.O. of the outflowing water periodically. If need be, aerate 
   the water to re-increase the dissolved oxygen.

   Be very careful with the regenerating compounds.
 
   Keep them away from children.

   After regenerating, dispose of effluent safely and immediately. See the 
   main text for methods of how to do so.

   Always rinse resin well after regenerating to remove acids and bases, 
   lest the pH will be too low or too high for the water to be used.

    Molecular Absorption Filters :

Of all the chemical filtration methods available to the Small Reef 
Hobbyist, perhaps the easiest to use, and certainly the easiest to install 
and include in the filtration set-up, is the very well known Poly Filter 
from Poly-Bio Marine.

A pad, or disks, are placed anywhere in the water flow, as long as they are 
in an area where water flows "through" them. They will work too if water 
just flows "by or over" them, but they will give you their full efficiency 
if water flows "through" them.

Poly Filters are a synthetic material impregnated with hydrophylic polymers 
designed to remove pollutants from the water by absorbing their molecules.

Some of the compounds these pads or discs will remove, or reduce, or keep 
in check, include the following :

--> phosphates : mineralized or ortho-phosphate,
--> copper : chelated and non-chelated
--> ammonia, ammonium ion
--> airborne pollutants from fumes, sprays, etc..
--> organic breakdown pollutants,
--> medicine,
--> amines
--> uric acid
--> tannins, phenols, humic acid
--> volatile organic compounds (VOC's))
--> organic phosphate

The pads, or discs, can be placed anywhere in the water flow. Moreover, not 
all of them have to be in the same spot. You can distribute them in several 
locations, wherever you have space, and wherever the water will flow 
through them. Additionally, feel free to cut them up in smaller pieces of 
any shape, and make them fit the space where you have decided to place 
them.

They change color as they become progressively loaded with the compounds 
they have removed, they start to change color. This allows you to determine 
when, in fact, it is time to replace them. Because they may also trap dirt, 
their true color may be masked. It is, therefore, a good idea to clean them 
once a week to remove particulate matter that they may have trapped. Rinse 
them under warm tap water and squeeze to remove dirt. Evaluate the color 
after you have cleaned the pads or discs. If they start to turn medium to 
dark brownish, it is time to replace them.

Here are some typical colors the pads or discs may take on, and the 
products that are involved. This list was provided by Ken Howery of 
Poly-Bio Marine Inc. :
-   Blue   : copper salts
-   Blue/greenish : copper ion  
-   Greenish/ yellow  : ammonia, amines
-   Orange : iron
-   Red : aluminum used in water treatment
-   Brown : normal organic load
-   Black : heavy organic load, high protein waste
-   Yellow : Ethyl Lead

I have personally used, and still use, Poly Filters for years. I would not 
run a tank without them. This is a truly superior product that you must 
include in your filtration set-up. I use a lot of them. Sometimes one pad 
per 25 gallons of water. If there was such a thing as a Reef Tank Best 
Product Award, Poly Filters should get it. Poly Filters are widely 
available and, because of their relatively long life, are a very cost 
efficient chemical filter.
The pads, when new, are white. Do not buy pads that have a faded yellow 
color. They may be old, and although they will still work, they will 
exhaust themselves rather quickly. Make sure the package is closed when you 
get it.

Some locations where you could place a Poly Filter : 
-   in the sump, close by the pump intake opening,
-   in the sump in a special compartment that is already there, or that you 
    have added,
-   in the pre-filter box, or overflow syphon arrangement,
-   in a canister filter,
-   in a chemical module of e.g. Lifeguard or PEP filters,
-   in the overflow corner box, if your tank was drilled for one,
-   inside the tank in an inconspicuous area with good water flow, for 
    example behind rocks, or dead coral,
-  and of course in the special canisters sold by Poly-Bio Marine.

Some Hobbyists dedicate a Poly Filter to remove copper from hospital or 
treatment tanks, and use that pad only for that purpose. Such is, of 
course, an excellent idea. So is having such a small tank running at all 
times. Just in case ! 

If you use Poly Filters to remove medications, use one pad per type of 
medication and remove it after the treatment is completed. Store the pad 
after letting it dry, and label it so you know what medication you used it 
for. Poly Filters do not remove gasses, so they will not affect your 
dissolved oxygen and carbon dioxide levels. That is a boon, because freshly 
added carbon will, for some time, lower the D.O. levels. The latter, in 
turn, affects your redox potential.

Keep a few spare pads around. When something just does not seem right with 
the tank (and such happens, believe me), add one or more Poly Filters 
immediately. Of course you must, in such cases, also check your water 
quality parameters, and make adjustments if necessary. Sometimes, however, 
things seem not right, and no cause can clearly be identified. As a 
precaution and partial or complete remedial, Poly Filters should be added 
to the system.

I indicated already that Poly Filters should be cleaned. Because even in 
the best filtered tanks small particulate matter always abounds, it is 
necessary to do so regularly. Make it part of your regular maintenance 
routine. Your water quality will benefit from it. And, when keeping Reef 
Tanks, it all boils down to water quality.

When placing Poly Filters in a canister filter, position them between 
layers of filter floss. This will reduce the amount of particulate matter 
trapped on the pads or disks, and make them perform more efficiently for 
you.

As far as I have been able to determine, Poly Filters will not remove 
ozone, and Poly-Bio Marine are looking into this. However, a Poly filter 
that has been in use for a while will reduce it, mainly because of the 
particulate matter it has trapped. Some carbon is, therefore, still 
necessary if you run a skimmer, or a reactor, with ozone injection.

We referred to pads and discs in this section. Although they both perform 
the same function, the discs are a much stronger variety of the medium. The 
latter also explains why they are more expensive.


[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]
SMALL REEF AQUARIUM BASICS
  
Additional Remarks on the Use of Activated Carbon :

Earlier in this chapter we looked at the uses of activated carbon. My 
intentions were not that say that activated carbon is not an efficient 
chemical filter. It certainly is. The point, however, is that in Reef and 
Marine tanks you can do better, for example by using Poly Filters or 
molecualr absorption discs.

Keep in mind also that there are many varieties of activated carbon offered 
for sale, to name a few :
  coal based, mixed  types
  bituminous
  lignite
  coconut shell
  vegetable base (other than coconut)

The better types of activated carbon are definitely lignite and coconut 
shell, the latter being the best one for our application. If it is not acid 
washed first, and then rinsed, both done during the manufacturing process, 
the effluent waters  pH will be too high. If you decide to use that type, 
make sure such was done, so the pH of your Reef does not get affected (as 
already indicated, usually upwards).

I personally prefer the small granules described earlier. These seem to 
give the best wetting of all the carbon. The latter means that all granules 
are exposed to the water that flows through the activated carbon, which is, 
of course, what we must try to achieve, as such ensures better adsorption, 
and cleansing of the water.

    Review of Filtration Requirements Discussed:

   Mechanical Filters :

   Use one or more mechanical filters and clean them 
   frequently.

   They can be before the trickle filter, and/or in the sump.

   Use a canister filter if an extra mechanical filter is necessary.

   Make sure they can be easily accessed.

   Don't use diatomaceous earth filters.

   Sub-micron filters should only be used intermittently.

   Filter floss is perhaps the most economical way to go.

   Repeat : clean filters regularly. Once a week is a minimum

   Biological  Filters

   Use an under the tank trickle filter or hang-on trickle filter.

   Select one that has most of the desirable features 
   mentioned earlier in the book.

   Make sure that it has a large sump area.

   Strong aeration of the biological chamber is a must.

   Fill it with plastic filtering media, e.g. balls or blocks.

   If it has a built-in skimmer, it should be of the right size.

   We prefer drip plates with tapered holes, over spray bars.

   1/4 inch thick acrylic material is recommended.

   Do not run too much water thru the biological chamber.

   Pre-filter the water that enters the biological chamber.

   Do not use plastic media that trap dirt.

   Repeat : blow lots of air in the biological chamber.

   Open up plugged holes in the drip plate if you see any.

   Syphons with a surface skimmer are better.

   Syphons with an automatic re-start are better.

   Use a properly sized pump and a float switch.


   Chemical Filters :

   Use molecular absorption filters liberally.

   We highly recommend  Poly Filters pads or discs.

   You must use some carbon as well, if you inject ozone.

   You can use both activated carbon and Poly Filters.

   We prefer small granules, about 4 mesh size.

   Change your activated carbon frequently.

   Make sure it does not leach phosphates in your water.

   It. should have been acid washed to prevent a pH rise.

   If you plan to use resins, read the earlier section  a few times.

Remember, now is the time to make the right decisions. Before you buy the 
equipment. Spend once, and acquire the right product the first time around. 
Remember too, that most of the above features can be combined in one and 
just one correctly selected trickle filter. Canister filters, where 
recommended, are optional, yet very desirable.

Foam Fractionators - Protein Skimmers

Yet another most controversial piece of equipment, although its use has 
greatly increased in the last few years, thanks to several articles on the 
subject in Hobby magazines. My own position is very clear : they are 
necessary, they are here to stay, they must be carefully sized, and you may 
have to use ozone with them if your tank carries a high load of animal 
life, and many tanks usually do.

Protein Skimmers, or skimmers, as they are commonly called, are as 
important a component of a Reef Systems as the trickle filter itself. They 
are not, technically speaking, "filters", but let's not get too much into 
semantics.

Skimmers are mainly used to remove organic matter and free floating algae 
from the water, before they have a chance to break down, reduce the 
dissolved oxygen levels, and stress the biological filter in the process. 
Skimmers also remove some ortho-phosphates.

Proteinaceous matter resulting from excess food, undigested food, animal 
excretions, algae die-off, small life forms die-offs, etc... starts to 
break down in the tank water. Bacteria that are part of this process 
require oxygen and get it from the water, making less of it available to 
the other animals, including the bacteria in the trickle filter who need a 
lot of it themselves. This, in itself, is a first stress factor on all the 
tank's lifeforms, and on the filters (especially the biological filter).

The second stress factor results from the intermediate breakdown compounds 
produced during decay and mineralization. Many of these can be noxious, or 
stressful, at best. Some of these include : indoles, phenol, scatoles, 
organic acids, amines, nitrosamines, amides, etc. Preventing this protein 
matter from breaking down to begin with, prevents the formation of these 
intermediate compounds as well. The net result is less pollutants, less 
stress, and higher dissolved oxygen levels.

Naturally, even the best foam fractionators will not remove all 
proteinaceous matter from the water, neither will they remove all free 
floating microscopic and other algae. But they will remove a great deal of 
them. The best proof of their efficacy, the one I always like to point to, 
is the composition, and appearance, of the liquid-paste-like matter that 
collects in the skimmer cup. Just take a good look at it sometime. If you 
had not had a good and efficient skimmer, all of that material would still 
have been in the water, either as decomposed, or decomposing matter, 
producing numerous by-products in the process (and stress).

Since it is clear that skimmers are an efficient way of removing 
undesirable matter from the water, the only question that remains is how to 
size the skimmer correctly. Often, you are at the mercy of the 
manufacturer, and his recommendations, as to what unit is intended for your 
aquarium. These recommendations are often erroneous. At least that is what 
I have found, when trying different size skimmers on the same tank, to 
determine which model, size-wise, gave the best results.

Since the recommendations I referred to seem to be erroneous, where do they 
come from, and why are they given? I can only assume that  they were 
arrived at by research at a time when Hobbyists kept mostly "fish-only" 
tanks, and that the recommendation only apply to such type aquariums. That 
would make sense, as it is unlikely that a manufacturer would knowingly 
give out wrong information. 

Since the type of tank we are interested in is totally different from a 
load, maintenance and filtration standpoint, I would like to suggest that 
you disregard those recommendations, and look at the following table that 
was painstakingly arrived at over many many experiments, and then after you 
have done that, make your own judgment:

Factors influencing columnar skimming :
    diameter of tube or chamber.
    length of tube or chamber.
    type of airstone used (bubble size)
    amount of air blown into chamber

Factors influencing size of skimmer :
    size of aquarium.
    load of aquarium.
    feeding habits.
    maintenance and husbandry techniques.
    sophistication of filtration.

Of the 9 factors listed, some are beneficial and some are not. For example, 
using the right kind of airstone is a positive step, over-feeding is a 
negative one. Some factors are influenced by others, e.g. the 
sophistication of the filtration depends not only on having the right 
filter, but also the right pump, blowing air into the biological chamber, 
having fine filters in-line, etc.

It becomes quite complex, therefore, to decide on what type of skimmer to 
buy. Our recommendation is : when in doubt between two models, choose the 
larger one of the two.

We suggest that you decide between 5 "general"  models :

     short and narrow diameter, 1 airstone.
     short and wide diameter, 2 airstones.
     tall and narrow diameter, 1 airstone.
     tall and wide diameter, 2 airstones
     venturi power protein skimmer, no airstones.
     Narrow is defined as three to four inches in diameter
     Wide is 6 inches or more
     Short is 18-20 inches of skimmer column (not total height)
     Tall is at least 36 inches of skimming height.

In the list that follows, circle the number of the situations that best 
applies to you, then add up all the numbers, or substract where minus 
figures are listed, if the situation applies to you. Once you have your 
total, refer to the recommendations at the end of this section as to which 
skimmer you should get. This is a fairly easy list to go through. If you do 
not want to write in the book, keep score on a separate sheet of paper.

Checklist for Sizing a Protein skimmer 
(for tanks up to 125 gallons) :                                      DEDUCT

-    You have a trickle filter that meets the requirements              
     outlined in this book  (deduct 6)                                 -6
-    You have a trickle filter that partially meets the 
     requirements outlined in this book                                 3
-    You are blowing a lot of air into the biological chamber          -1
-    The air pump you are using is small, old and you have 
     not recently changed the diaphragm                                 2
-    Your are not blowing any air at all in the biological 
     filter chamber                                                     4   
-    You have no trickle filter                                        20
-    You have a trickle filter with DLS (<6 months old)                 4  
-    Your trickle filter contains  DLS and is at least 6 
     months old                                                         8
-    Add 3 points to your score per 10 gallons of water 
     in your system. Not including water in the sump.....               3
-    Tank has a low biological load ( be honest)                        2
-    Tank has a medium load                                             4
-    Tank has a high load                                               8 
-    Tank has a very high load                                         15
-    You are not using molecular absorption filters 
     (6 discs or one pad per 25-30 gallons)                             5
-    You are using too few molecular absorption filters
     less than one per 25-30 gallons of water, but more
     than 1 per 50                                                      2
-    You are using about 6 M.A. discs, or one pad, per 
     25-30 gallons                                                     -2
-    You are not using activated carbon                                 2
-    You clean your mechanical filters more than once a 
     week                                                              -4
-    You clean your mechanical filters at least once a week            -1
-    You clean your mechanical filters about once every 
     2 weeks                                                            5
-    You  clean your mechanical filters very infrequently              10
-    You are not planning on using ozone                               10
-    You feed more than once a day                                      6
-    You feed about 4 times a week                                      2
-    You do not remove dead algae                                       4
-    You use a Nitrate reducing compound                               -6
-    You do not use such a compound                                     4
-     You are using a cartridge type mechanical filter, and 
      change it each time required                                     -3

  1989 A.J. Thiel. This checklist may be reproduced only if the name of 
this book, and the address of Aardvark Press is mentioned.

Let us run through a few examples : 

You have a 55 gallon tank, with  trickle filter but it does not meet all 
the requirements outlined in this list, the load is medium, you feed 3 
times a week and you plan to use ozone. 2 Poly Filters are used and so is 
X-nitrate. Your air pump is a fairly recent Schego, and your husbandry 
techniques are good. You clean all mechanical filters at least once a week 
: your score would be 26.5. If you were running the same tank without a 
trickle filter your score would be 49.5.

Same tank but with a heavy load, no Poly filters, and no X-nitrate and you 
do not really clean your mechanical filters every week : the score would be 
42.5, and if you did not have a trickle filter, it would be 65.5 or more.

To decide on which skimmer is recommended for your tank,  look at which 
category your total fits in :
    Up to 20 points : short and narrow
    21 to 30 points : narrow and tall
    31 to 49 points : wide and short
    50 or more points : use a wide and tall, or a Venturi skimmer.

If you cannot find a skimmer of exactly the size recommended, it would be 
wise to buy a size larger than the recommendation. This will ensure that 
you have at least the amount of skimming that is, in my opinion, necessary.

Another way to use this checklist, is to determine which factors influence 
the skimmer size heavily, and then make sure you do not fall in that 
category. For example cleaning your mechanical filters at least once a 
week, and using ozone, takes a total of 20 points off your score.

Take the number of airstones we recommended into account as well, and 
remember that airstones need to be changed about every 3 to 4 weeks 
maximum. This will ensure that they always produce small bubbles, and skim 
more efficiently.

I strongly feel that a Reef tank needs to be run with a good and properly 
sized foam fractionator, protein skimmer. My experience, over and over, has 
been that its use results in greatly improved water quality, higher 
dissolved oxygen levels, and a higher natural redox potential.

Most Hobbyist will find that the protein skimmer they need will not fit 
underneath their aquarium cabinet. That may be one of the reasons they 
resort to either not using one, or using one that is too small. Such will, 
I feel, lead to problems with water quality, which in turn will lead to 
problems with the animals, and seemingly uncontrollable outbreaks of 
micro-algae, parasites and disease.

Skimmers can be hidden in special cabinets placed next to the tank, or if 
you are in the category that requires only a short and wide type, it may 
fit underneath a different type of cabinet. You may have to make the 
special cabinet yourself, or have it made at some local carpenter's work 
place. Another alternative is to use a Venturi skimmer, because they are 
smaller and "will" fit underneath the tank.
At the time of this writing only 3 types of Venturi skimmers were available 
in the North American market :

   Tunze
 
   Hippocampe P Klaes

    Thiel-Aqua-Tech 

Venturi skimmers tend to cost more money than columnar ones, but you will 
not need an airpump, and you also do not need air stones. Make sure that 
the model you decide on can be operated with ozone, as you will probably 
end up wanting to use it. 

Determining the size of the protein skimmer and the number of airstones it 
should have, is only part of the equation. We still need to determine how 
much water to flow through the skimmer, and how much air should be used.

For every "load" there is an ideal flowrate, and that flowrate cannot be 
determined unless you have a redox controller. Since this is not a unit 
that we will include in a basic set up, we need to look for other ways of 
approximating that gph,A and end up with an efficient skimmer. To do this, 
we need a few more explanations about protein skimmers.

As indicated already, the efficiency is determined by :
    Contact time of bubbles and water
    Size of the bubbles

But also by, in my opinion,
    materials used in the construction
    shape of the skimmer
    actual water level in the skimmer
    salinity of the water
    use of other additives

Air/Water Contact Time :

Tall skimmer columns obviously result in longer contact times. The water 
must travel downwards for longer, and the air must travel upwards for 
longer as well. The combination maximizes contact time.
Equal flow rates through tall and short skimmers obviously result in 
different contact times. Water should be flowed slower through short 
skimmers to make it remain the skimmer longer, or it should be flowed 
faster, to increase the actual amount of times it goes through the skimmer. 
In my experience the first alternative works better.

Size of Air bubbles :

As already indicated, wooden airstones are still the best for fine bubbles. 
Lime wood is my preferred, although oak works better but requires a much 
stronger airpump, something most Hobbyists do not have. Wisa pumps, 
however, will blow through oak air stones.

We recommend you use limewood airstones, and change them every 3 weeks if 
you use ozone, and every 4 weeks if you do not. Although they used to be 
hard to get at one point, they are now plentiful.

I have also tried ceramic, bonded glass, porous polyethylene types, and 
although some of them do give off real fine bubbles, they are either not as 
small as those out of limewood, or you need an extremely powerful air pump, 
not something most Hobbyists have.

The exact amount of air that needs to be blown through the skimmer is very 
hard to determine and varies greatly. You may want to use the following 
guideline : blow as much air as is required to make the whole inside of the 
skimmer look like a milky white mass of water. Whisper 1000 air pumps, or 
similar will do the job in most cases. If you need a stronger pump, use a 
Wisa 100 or a 300, or 2 Whisper 1000's, one on each airstones (combine the 
output of the 2 air streams of each pump with a Tee and then connect it to 
each air inlet).

Shape of the Skimmer :

Most skimmers are built using round plastic tube (acrylic). The main reason 
for this shape, is that it provides an even and easy circular downflow of 
the water, from the top of the skimmer, where the water enters, to the 
bottom, where it exits. Circular flow increases the amount of time the 
water is actually in the skimmer column, and as a result better skimming is 
achieved. 

This is by no means the only shape that one can use. My company makes 12 
and 18 inch "square" protein skimmers for very large installation (several 
thousand gallons), that outperform round models, and cost considerably 
less. If properly constructed, such units are extremely efficient. 

It is, however, a fact that most of the skimmers you will run across , and 
that you will use, will be round. The water entry fitting should be angled 
in such a way, that the water is pumped sideways against the inside wall of 
the skimmer, and slightly downwards. This will ensure that the water 
rotates, and takes longer to get to the bottom of the skimmer.

Salinity of the Water :

Water of a higher salinity skims (foams) better than water of lower 
salinity. We have little choice over the salinity, as we have to stay 
within a very narrow range of 1.018 to 1.026 specific gravity. Most 
Hobbyists maintain their tanks at 1.023, which is also what most authors 
recommend. The point to remember is that skimming efficiency will diminish 
if you lower the salinity too much.

Water level in the skimmer :

The water level in the skimmer determines the type of foam that runs over 
the top, and into the collection cup of the skimmer. Wet foam, mostly plain 
water, is not properly skimmed water, and contains much less of the organic 
and other elements we wish to remove, than a dry foam, that is heavily 
concentrated, dark in color, and thick. 

You must take care to regulate the height of the water in the column so as 
to obtain dry foam at the top, that runs over in to the cup from time to 
time. This may not be a one time task, as the way the water skims changes 
depending on salinity, load in the tank, feeding, etc. Skimmers must be 
monitored regularly, and adjusted from time to time to ensure optimum 
efficiency.

The color of the material that collects in the cup should  be brown, green, 
black, or some dark color close to any of the three mentioned. Clear fluid, 
even if slightly yellowish, is not  really what you want. Further 
adjustment of the skimmer's water level is necessary when that happens. 
Alternatively, try injecting more air, and/or changing the airstones. Often 
too, the fitting that you attach the hose to at the end of the airstone may 
need to be tightened more. If it is somewhat loose, not all the air goes 
through the wood. Some comes out directly, around the that fitting and 
forms large bubbles, reducing skimming efficiency.

Water Additives Used :

Many water additives will change the way in which the water foams. Some  
can really make the skimmer get totally out of hand. Such foam is mostly 
water that does not contains the extra material that you want to skim out 
of the tank.

Before using any additives, it is important that you try out a very small 
amount of them, to ensure that you will not have to re-adjust the skimmer. 
Many products, unfortunately, fall into this category. Running a skimmer 
with 6 or more inches of very wet foam at the top is counter productive. If 
you must use these elements, switch the skimmer off for a while (several 
hours, to over a day for some).

Certain trace elements will not make your skimmer foam more than it 
normally does. One such products is sold by T-A-T, but there are others.

    Optimum Water flow :

Once you understand what will affect the operation of your skimmer, and 
made the necessary adjustments, you are ready to optimize the amount of 
water flowing through the skimmer. We assume, for this example, that you 
have followed the checklist, and that you have the right kind of skimmer, 
the one suggested and recommended for the type of tank that you keep.

-  Take a small jar that can be closed airtight. The latter is very 
important. You must be able to fill it, and close it so no air whatsoever 
can enter the jar.
-  Perform a dissolved oxygen test. Note the result.
-  At the same time as you take water for your dissolved oxygen test, fill 
another jar completely, making sure that no air is trapped in the 
container.
-  Store this jar with the water for 48 hours, in dark place.
-  Flow the content of the aquarium once, per hour, through the skimmer. 
For ease of calculations use the rated content of your tank.
-  Let the skimmer run for 48 hours.
-  Perform a dissolved oxygen test on the tank water, and a dissolved 
oxygen test on the water you stored.
-  Compare the results of the the oxygen test you did two days ago with the 
one you just did. If it is lower, you are not skimming enough, and either 
your skimmer is too small, or your load is too high.
-  Now test the water you put away for 48 hours. Compare the result with 
the Dissolved oxygen level you had the day you took this sample. Write down 
the difference.
-  Refill the jar with aquarium water, and store for 48 hours.
-  After 48 hours test the sample. Write the number down.
-  Compare this result with the one you got when you took the sample. Note 
the difference.
-  If you are running enough water through your skimmer the oxygen deficit 
should have gone down.

To illustrate this :

Flow rate          Day         D.O.        D.O.(48)            Difference

1 x tank            1          6.80          4.50                2.30
                    3          7.00          4.80                2.20

At the above flow rate your tank's organic load went down; the skimmer 
removed it. How do we know that ? By looking at the dissolved oxygen (48) 
numbers, and comparing the first one you had with the second set. We are 
not interested as much in total dissolved oxygen, as in the difference 
between the first and second number. Notice that for the first set the 
difference was 2.30 (the deficit), and in the second set it was only 2.20, 
slightly less. Not much, but still slightly less.

Another example :

Flow rate          Day         D.O.        D.O.(48)            Difference

1.2 x tank          3          7.00         4.80                 2.20
                    5          7.20         5.60                 1.60
1.5 x tank          7          7.50         6.20                 1.30

All numbers in mg/l. Numbers were achieved on a 40 gallon reef tank, using 
a  30" x 6" skimmer from Thiel-Aqua-Tech. Tank had a heavy load of fish and 
invertebrates.

What you now want to do, is to change the flow rate through the skimmer and 
determine at which level, the difference between the D.O. test, and the 
test done on water taken at the same time, but stored for 48 hours, is the 
smallest. At that level the skimmer is removing the most organic material, 
and is running more efficiently. The reason for this is, that the higher 
the organic load left, the more oxygen will be consumed by bacteria in the 
48 hour elapsed period, the greater the difference in the D.O. levels will 
be as well.

This may not be the quickest way to determine optimum flow rates, but it is 
certainly a method that is both easy and inexpensive, does not require 
elaborate equipment, and can be used by any Hobbyist.

Protein skimming is a special form of filtration, and the name is a 
misnomer. Skimming removes more than just organics (protein). Trace 
Elements, vitamins, fertilizer, and other elements will be removed as well. 
You must be aware of this, and replace these elements on a regular basis, 
lest you will run a tank with a deficit of beneficial compounds. 

How much you should add is very hard to know, but add you must. Refer to 
the recommendations made by the manufacturers of the products that you use. 
If, in addition to a protein skimmer, you also inject ozone, you will need 
to add even more additives, as ozone breaks these compounds down rather 
quickly.

If you happen to be in the market for a skimmer and a filter, consider 
buying a trickle filter that incorporates a Venturi skimmer. Your total 
expenditure will be less, and you will have a skimmer that not only fits 
underneath the tank, but that works as efficiently as a 4 foot column 
(applies to T-A-T models).

Keep the following in mind when selecting and running an outside skimmer:
-  Size the unit properly. Use the checklist as a guide.
-  Change the airstones every 3 to 4 weeks.
- Adjust the water level so you produce only dry foam.
- Try to determine the optimum flow level.
- If you don't, flow 1.25 to 1.5 times the tank's content through the 
  skimmer.
- Empty the cup regularly, or make it run into a bucket that you then 
  empty.
- Adjust the water level in the skimmer as needed. This means
  and we have said it already, monitor your skimmer on a regular basis.

     Venturi Skimmers :

Recently, more efficient and more compact protein skimmers, foam 
fractionators, have appeared on the market. Of the three models that were 
available at the time of this writing, only one was made in the United 
States.

Venturi skimmers do not require an air pump, but can be operated with one 
if you want to. The principle behind these skimmers has been around for 
along time. As water is forced through a special fitting, a differential 
pressure is created, and this differential pressure sucks air into the 
water stream, and breaks the air up in very small bubbles, giving the 
efficient skimming we instanced.

The more forceful the water is pushed through the Venturi valve, the 
greater the differential pressure, and the more air is being sucked in. 
Water flow levels needed vary, depending on which Venturi skimmer you 
purchase.

It may happen that the pump you are using to run your Venturi skimmer, is 
not pushing enough water through the Venturi. As a result not enough air 
for efficient skimming is being pulled in, and you have the impression that 
your unit is not working properly. There are two ways around this : one, 
push more water through the Venturi, and if that is not possible; two, 
attach a strong air pump to the intake of the Venturi valve and blow air 
into it. This will compensate for the lack of high water flow.

Venturi skimmers are appealing to many Hobbyists because they are compact, 
and will fit underneath the aquarium cabinet. If you plan to use ozone with 
such a skimmer, make sure that the unit you are planning to acquire can 
function with it. Some cannot, as a lot of Hobbyists have found out.

A Venturi skimmer's efficiency is determined by the quality of the 
"venturi" valve, and how it is constructed. Ideally it should have a Pitot 
tube inside. If not, the venturi still works, but may not draw air in as 
forcefully.

More details on "Pitot" tubes can be found in Advanced Reef Keeping Made 
Simple. Regardless of whether your skimmer has such a tube or not, more air 
can always be blown into the skimmer by means of a strong air pump, if such 
is necessary. Remember: the amount of water going through the skimmer is 
important, but what is more important is whether or not the skimmer 
operates efficiently, and that is determined by the mixture of air/water, 
and the size of the bubbles you generate. Some companies, e.g. 
Thiel-Aqua-Tech uses both "molded" and hand made Venturi valves. Molded 
valves obviously are more efficient but are more expensive.

If you have to make a choice between a columnar and a Venturi skimmer, the 
Venturi model will, in most cases, outperform the columnar one, especially 
if it is equipped with a molded venturi.

  Conversion and Hang-on Units (Biological filters)

Several manufacturers now offer so-called conversion units, mostly geared 
towards the smaller tank, e.g. the 30 to 70 gallon range. Many will perform 
an excellent job for your aquarium, as long as you select the correct size 
for the tank you have, and the load you will keep.

What is most important in those units, is that the water is dispersed very 
evenly over all of the biological materials inside. Because you have less 
of it, you must use it more efficiently. This is where drip plates with 
many small holes are a must. It is probably best to actually "see" the unit 
before you buy it. Look through the magazines as well. Pictures can tell a 
lot too. One really excellent unit is made by World Class Aquarium, of 
Brooklyn, New York.

Several commercial units are available. Moe (1989) describes how you can 
make one yourself in "the Marine Aquarium Reference". That 500+ pages book 
contains a wealth of such information, and is well worth the investment of 
around 22.00 dollars. Look through the magazines, or at your local Pet 
Store, and you will usually find a selection of them.

Because of the reduced size these filters do not necessarily accommodate 
all of the extras that we have recommended earlier in this book. Select one 
that has as many as you can find, and supplement the system with additional 
filtration means, e.g. canister filters filled with Poly Filters, activated 
carbon, X-nitrate, or similar products that we have already described.

In these filters we recommend that you use plastic filtering material that 
definitely does not trap dirt . Since this is a smaller filter, you 
certainly do not want to have to clean it and destroy a great deal of 
bacteria in the process. Cubes, Blocs, Spheres, Techs, Balls, Packs, disks, 
and the newer Super-Techs will work well. Blocks and Cubes are especially 
well suited.

Remember : you must blow air into the biological chamber as this will 
greatly improve the efficiency of your filter. The biological processes 
that take place in the bio-chamber require a great deal of oxygen, because 
the bacteria that "perform the work" are aerobic. Not blowing air into the 
filter is, to make an analogy, like driving your car in third gear and 
never moving up to fourth or fifth, or, back to our filter, only using part 
of the available biological activity of the filter.

Make sure too that the conversion unit is of the "trickle" type, and not a 
submersed biomedia type. Although the latter units work too, of course, 
they operate at much lower levels of biological activity than the other 
types.

 

[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]
2.  Water Sources, Uses and Treatment 

  Introduction 

         Up  to  this  point, we have spent the greater part of this book  
talking  about  how  to  maintain  the  water  quality  necessary to keep  
invertebrates,  corals,  fish  and other lifeforms normally added to Reef  
Tanks, in much better than average shape and condition.  We have not said 
a  word yet about the water itself and its sources, before it is added to 
the  tank.  Neither have we said anything about how water can, or should, 
be  treated before it is used for the marine and reef aquarium.  

          Besides  using  it to fill their tanks, Hobbyists use water for 
the  following three main purposes :         
         - to add water, when water changes are made,
         - to regularly replenish evaporated water,
         - when diluting water additives e.g. carbonate hardness liquids,
         trace elements, kalkwasser (limewater) vitamins, etc.  

         Whatever its purpose, the water used should be of superior qual-
ity.  What  the  latter means, and I have  not  seen it defined frequent-
ly,  is  that  all toxic and all unwanted matter, compounds, elements, or
whatever   they    may  be  called, should have been removed through some 
process  or  another,   prior to the water being used.  In most cases  it  
is   the   Hobbyist  who decides  which cleaning process will be used.  I 
say  in  most  cases,  because  a number  of Hobbyists do not cleanse the  
water   themselves,   rather   they   buy   water   that has already been 
treated  (e.g.   distilled,  or purified as it is now  called by the USP) 
either from a Pet Store, or from some other supplier.  

         It is important to understand that "ensuring that the water used 
is   of  good  quality",  is  a  most  consequential  part  of  good tank 
maintenance.  Indeed, once the  water is in the tank, Hobbyists spend un-
told   hours,   and   money,  trying  to  ensure  that it remains of good 
quality.   Adding  bad,  or  inferior, quality water to begin with, does, 
therefore,  not  make  sense  at   all,  especially when you consider the 
efforts  and  money  spent  to upgrade,  and maintain, the quality of the 
water  once  the tank is up and running, and  contains a lot of expensive 
and precarious livestock to boot.  

         As  we  shall  see later in this chapter, there are many ways to  
purify,  cleanse,  or simply said  "clean up" water before it is added to 
the  Reef,  or fish tank. More important than which exact form of purifi- 
cation  is   used, is the fact that some form "is".  And let me say right  
away   that   you  do not have to get extremely fancy either, to get good  
water  quality.   There   are  many  ways  to  do  so that are both inex-
pensive, and efficient, in terms  of the effluent water produced.  

Water Sources 

         Freshwater  sources  are  the  most  commonly  used ones for the 
purposes  already mentioned, and include the following: 

         - tap water
         - well water
         - lake water
         - river water
         - distilled or purified bottled water
         - mineral water (bottled)
         - spring water (bottled)
         - de-ionized water from outside vendors (bottles, bags) 
         - reverse osmosis water from outside vendors 
         - some even use or have access to lab quality water.  

         Purified  seawater  sources  are not as frequently used, but are  
available  in  certain  parts  of  the  country.   This is, of course, an 
excellent supply source, and its use should be encouraged.  Unfortunately 
not  many   Hobbyists  are lucky enough to have it available.  If you do, 
consider using it on a regular basis, or from time to time.  You may, for 
example, not wish  to use it to perform all water changes, but you could, 
to keep costs down,  use it every other time, or every third (etc.) time.  
Because of its  "completeness" it is hard to beat its quality.  

Water Uses 

         Top-Offs :
         Replenishing  evaporated  water  with cleansed "freshwater" is a 
task no Hobbyist can avoid, as no one has control over evaporation.  Drip 
systems that operate on the "water level in the sump basis" are simple to 
install, and should be used if at all possible. They are very inexpensive
and can be easily home made .
            
         The diagram at the top of this page shows such a system.  

         Note the following about its operation :
         -  the freshwater bottle, or canister, must be "airtight".  This 
is   most  important,  as if it is not, the bottle will empty itself in a 
matter of  minutes or even less.
         - the principle behind this system is the same as the well known  
water  dispenser in offices, where a large, usually 5 gallon, bottle sits 
upside  down in the dispenser.  As you push the manifold, water comes out 
of the spout.  As  the  level inside the dispenser becomes lower than the 
bottom  of  the  neck of the  upside down bottle, air gets in the bottle, 
and water comes out, until the end  of the neck of the bottle touches the 
water again.  You can notice this happening  when  air suddenly rushes in 
the  upside  down  bottle  (while  water gets out at the  same  time, and 
refills the reserve container inside the water dispenser).
         -  in this system the principle is exactly the same.  As the end 
of   the  small  internal  diameter  tubing  is less immersed, because of 
evaporation, it  will eventually be slightly out of the water.  This lets 
air in, and water out of  the reserve container, and achieves the desired 
result of adding water to the  sump.
         -  the container, or bottle, must be rigid, so it will not crush 
as   the  vacuum  inside  of  it  becomes  greater  as it empties itself.  
Rigidness  is  most   important,  or  your  system will not work.  If the 
container  collapses  on itself,  all water will come out and be added to 
the system.  Not what you are trying to  do.
         -  use  small internal diameter hose : 1/4 to 3/8 inch will work  
fine.  Smaller  may not work in all cases (especially if the run is long, 
and the  container  small).  Rigid hose, or small diameter pipe will work 
even better.  I use  3/8 internal diameter pvc pipe.
         - Attach the bottle or canister with some sort of bracket, so it  
can not  move up or down.
         - Replenish the bottle whenever required.  The larger the bottle 
or  container is to begin with, the less often you will have to do so.  

         Alternatively  you can, of course, as many Hobbyists do, perform  
the  top-offs  manually, adding the necessary amount of replacement water 
by  hand.    Make  some  sort of a mark on the side of the trickle filter 
sump,  so  you  know  where the  level should be, and when it is not, add 
the  required amount of "treated"  water .  Adding raw water, for example 
from  the  tap, can be done, but only if you  are sure that that water is 
safe  to  use  on your tank.  This can only be  determined by  testing it 
extensively,  something the average Hobbyist cannot do, or  normally does 
not do.  

         To play it safe, treat the water by running it through some form 
of   chemical filtration medium.  I recommend Poly Filters (from Poly Bio 
Marine,  or  molecular absorption discs from the same company highly, and 
use them myself all  the  time.  

          Certain  manufacturers  sell  small  dosing pumps that will add 
water   drop-wise to your tank.  Two such companies are Tunze and my own.  
A  small dosing  pump to add drops should not cost you more than $160.00.  
The device can also be  used,  of course, for adding certain additives at 
the  same  time.   Not  all  types  of   pumps   can  handle all types of 
additives   (e.g.   compounds  that  contain   particulates  can  not  be 
dispensed  with  small  diameter  peristaltic  pumps, as the tubing would  
soon  lose its vacuum, making the pump inoperative).  

          I  also  use  a  pump  to  add "Kalkwasser", meaning limewater, 
drop-wise  to the Reef, to maintain a high calcium hardness (not the same 
as  carbonate   hardness).   This  greatly  benefits  my  corals and also 
results  in  red,  pink,  purple  and greyish coralline algae growing all 
over the aquarium.  This a diaphragm type  pump,  not a peristaltic one.  

         If  the doser pump (often a small peristaltic pump) that you use  
delivers more than the amount of water that you want to add to your tank, 
all  you   need  to  do is to run it for a lesser number of hours (not 24 
hours,  round  the   clock).   Do so by using a timer.  Radio Shack sells 
really  excellent  Micronta brand  timers  that are inexpensive, and will 
do the job just fine.  

        It is also recommended to place a small airstone in the container  
that   holds  the  water from which the doser is pumping, and run a small 
amount  of   air  through it.  This is especially handy if you dispense a 
mixture  of  compounds,   as  i  t  will  keep all parts in solution, and 
prevent  the  heavier  ones  from   settling to  the bottom (for example, 
calcium, vitamins, and some fertilizers).  

         If  yours  is the physical manual system of topping off, add the  
water  slowly,  and  preferably to the sump of the trickle filter, not to 
the  tank   itself.   It  will  mix  better  in  that  fashion.   Top-off 
frequently, perhaps every day or  every other day, if necessary.  

         Simpler Drip Systems :

         Yet  another  way  to  top-off  your  tank is with a simple drip 
system,  adjusted  to  deliver  the  quantity of freshwater that you need 
every  day.   This spreads the amount added evenly throughout the day and 
keeps  conditions  really   stable  in  the tank.  All you will need is a 
reserve  vat,  at  piece of airline tubing,  and a  small clamp to adjust 
the  flow.   Start  up the syphon effect, adjust the  flow, and your drip 
system  is  up  an running.  Slow drip systems can be somewhat  tricky to 
adjust.   Because  the  tubing  out  of which the water is coming is very  
restricted  ,  they  may  stop.   Frequent  adjustments  may therefore be 
necessary.   Try  it,  and if  it is too cumbersome for you to deal with, 
resort to some other method  described here.
      
         Water Changes:
         There  are many differing theories on water changes.  Some go as 
far  as to advocate that with "their" systems no water changes whatsoever 
are  necessary, ever.  This may have been true for them, but it has never 
worked for me.  Some  form  of water changing seems necessary, regardless 
of  how  sophisticated  your  system   becomes.   I have said so for many 
years,  and to date, even with all the  sophistication of my own tanks, I 
am still convinced that water changes are a must.  

        Since this book is dedicated to the small reef tank, I definitely  
recommend that you perform water changes on a regular basis.  I have long 
held  the   theory, based on my own experience, that the best results are 
obtained when  water changes are both :           
      
         - frequent         and        - small 

          rather  than  infrequent  and  large.   The  reason for that is 
simple:   small  and  frequent  water  changes  do  not  change the water 
composition (chemistry)  as much as large ones do, putting less stress on 
the  fish,  corals  and   invertebrates.  The changes referred to include 
temperature,  pH,  salinity, osmotic pressure,  ionic balance, percentage 
make-up  of  minerals and individual chemical elements,  and  so on.  You 
would  be  amazed  what  a 20 or 25 percent water change can do to  those  
conditions !   

           I  have, for years, recommended that you change 4 to 5 percent 
of  the tank's water per week, or 2 to 2.5 percent every 3 days.  This is 
simple  to  do   for  most  Hobbyists,  as  it  normally does not involve 
handling  a  great deal of  water.  For example, if you  have a 55 gallon 
tank, change about 2.5 to 3 gallons a  week,  or about one gallon every 3 
days.   Don't bother being totally "accurate",  round  the numbers off so 
they  match  some known container that you use (bucket,  jar, old plastic 
water bottle, etcetera).  Small water changes have one more  benefit :
you are less likely to make a mess by spilling water.  

         Additionally  things  cannot  get  out of hand that much either,  
because  you   perform  water changes every couple of days.  As a result, 
noxious  elements  cannot accumulate to any degree, and pollution is much 
less  likely  to  be  present   in such amounts that it would cause undue 
stress  on the tank lifeforms.   Examples of  this include phosphates and 
nitrates, to name just two.

         How do you change water ?  

         Manually  is the most frequently used method.  Remove the amount 
that  you  are going to replace first, then add the new water slowly, and 
preferably to the sump of the trickle filter.  

         It  cannot be stressed enough that both salinity and temperature  
need  to  be adjusted beforehand.  Perhaps, because we are dealing with a 
small amount  of water, exact, precise, adjustments are not required, but 
the salinity and  temperature must be approximately the same, as those of 
the  water  in  the tank.  You  do not want to add water at a temperature 
that  is  much  much  colder, or much  much warmer.  If the difference is 
only a degree or so, and the water is added to  the sump, no harm will be 
done.   The  same applies to salinity, although in this  case, you do not 
have  as much latitude.  Best is to keep the differences as small as  you  
can.  

         Use  water  from a vat where it was prepared beforehand.  Do not 
make up the mixture right then and there. If you do, all of the salt will 
not  be dissolved properly, and adding such water to your tank will lower 
the redox  potential of  your aquarium quickly and drastically, stressing 
all  lifeforms  in the tank.   I have seen the redox potential go down by 
over 100 mv several times, during  testing  (Thiel Lab.  Bk 23).  

         Keep  the  recommendation  made  earlier  in mind.  Change small 
amounts of water frequently, not large amounts infrequently. Change water 
on a regular schedule, and stick to that schedule.  It will be easier for 
you  to remember to do so, for instance, if you always perform your water 
changes on, say, Fridays or Saturdays.  

         Automatic  water  changers are now being installed more and more  
frequently  ,  and are both simple to set up, and inexpensive to acquire.  
Check the diagram below for more information :
         Notes of importance :
         -  To install an automatic water changer, you need to be able to  
drain  the  excess water that will accumulate.  This requires either that 
it  flow into  a vat of some sort, to a water drain in the floor, or to a 
sink (by means of a small pump and hose or pipe).
        -  Since, more than likely, only a very small amount of water
will need to be changed, you will only need a very low output pump.  That 
is the  reason a power head type pump can easily be used.  Often even the 
smallest ones will  do.
         -  I recommend using a digital timer.  Such timers can be set to  
trigger  at on/off cycles of very short intervals, for example, 1 or 2 or 
3  minutes.    Mechanical  timers  usually  work  only in 15 or 20 minute 
intervals.   Letting the  pump run for that long may move more water than 
you  want to, especially if you  keep a  small tank.  Indeed, if you have 
a  55  gallon  tank for example, and you wish  to change 1 percent of the 
water per day, you will want to change only 0.55  gallons,  meaning about 
half a gallon.  That is not very much, and only very small  pumps,
running for a very short amount of time will allow you to do so.  

         If  your  pump  still  moves too much water, notwithstanding the  
digital  timer's  setting  to its minimum cycle (usually 1 minute), put a 
C-clamp  on  the   output  hose  of  the pump or power head, and close it 
gradually  more  and more,  until the right amount of water is moved from 
the reserve vat to the tank (or  sump), in  the minimum on/off cycle your 
timer allows.  In fact, anything that  restricts the  output of the pump, 
respectively  power  head,  used,  will do the job.  Small  ball  valves, 
shut-off valves, and the like can be used, but be sure that they  contain  
no metal parts, except 316 SS.  

         -  I suggest that you do place an airstone in the reserve vat to  
keep the  water moving around.  This will keep it properly mixed and also 
oxygenated.    Water  reserve  vats must be cleaned from time to time.  I 
suggest  at  least  once  a   month.   This  will  prevent  sediment from 
accumulating, and possibly breaking down  into  undesirable compounds.
         -  Since  this  is "water-changing" water, it has to be prepared  
first, and  salt added.  Preferably use a salt that is low in phosphates, 
nitrates,  and   other  impurities.   Most  nationally  sold  brands  are 
excellent  of  course.  We use  Tech-Reef Salt and Hawaiian Marine Mix on 
an alternating basis, and supplement with Reef-Elements, Vita-Trace, KSM, 
Iodine Supplement, and the new  "Tech-Liquid-Gold"  very special nutrient 
for fish and corals.  

         Gravity feed water changers
         Place  a  vat  with prepared salt water higher than the tank, or  
higher  than  the  sump  of  the  trickle  filter.  This will allow it to 
gravity feed downwards.  

         Attach a small diameter hose to the vat and guide it to the
sump.  Install  a  solenoid  valve and a timer (as shown in the diagram).  
Set  the  time  for   minimum  on/off cycling, clamp the output hose down 
until  only  as  much water is  delivered as you actually want to change.  
The diagram shows exactly how to set  such a  system up.  

         Solenoids  can  be  obtained  from  companies dealing with fluid  
processing, scientific supply places, and some plumbing supply companies.  
One  company   that offers a large selection of 110 volt, 2-way solenoids 
is  Richdel/Garden Centers, in Carson City, Nevada.  Another source is W.  
W.  Graingers.  

 

 

 

 

 

 

 

         Evacuating Water from the sump (if you do not have a floor drain 
to  which it can be guided) 

        Even  if  you do not have a floor drain, you can still install an  
automatic  water changer, providing you are prepared to take some time to 
install  the required components seen in the diagram below (not to scale.  
May look  complicated to set up, but is in reality not) :  

         All  in  all,  your  expenses will amount to the cost of a float 
switch   and   a power head (which you may already have).  You must use a 
float  switch  that   allows  you  to control a "high" level, not a "low" 
level (the type used to protect pumps and prevent them from running dry).  
Best,  of  course,  would be to evacuate the water that the power head or  
small  pump, is removing from the sump, directly to a sink.  If you use a 
vat,  use  a   large   one,  so you do not have to empty it all the time.  
Adjust the level at which the float switch triggers, over a few trial and 
error sessions, until you are satisfied it does so at the correct level.  

         As  water  is  added by the water changer, the level in the sump 
will  rise,  since  more  water is now in the "system".  This extra water 
will collect in  the sump.   

        The float switch attached to the power head senses a higher water  
level,   and  triggers  the  power  head (or small pump) to start pumping 
water out of  the trickle filter's sump.  This water is then collected in 
another vat, or  guided directly to a sink by means of flexible hose.  

Treating the Water before it is used 

         Mechanically 

         Mechanical  filters are meant to remove dirt, detritus, particu-
late  matter,  debris,  etc.   from  the water before it is being treated 
further.   You are  familiar with mechanical filters, because you already 
use them on the tank  itself.  They are often referred to as fine filters 
or pre-filters.  

         A  canister  filled  tightly  with filter floss, or some similar  
material  will  do  the  trick for rough type impurities.  If you want to 
filter  down  to  the smaller material you will have to resort to the use 
of filter cartridges.  

         Such  cartridges  do  a fine job, but the cost of using them can 
creep   up  on  you  quickly.   You are probably acquainted with "micron" 
filters, rated in  values such as 100, 75, 50, 25, 10, 5, 1 and some even 
less  than  one  micron.    Keep  the  following in mind when selecting a 
micron  cartridge  of any type of rating  : there are two types, referred 
to as "nominal" and "absolute".   

         Absolute  means  the  cartridge does not let any material larger 
than   the  rating through, nominal lets some through.  For example, a 50 
micron  nominal   cartridge will let some 60, 70, etc.  material through; 
an absolute 50 micron  cartridge will not.  Absolute rated cartridges are 
quite more expensive than nominal  ones .  If you plan on using this type 
of mechanical filtration, stick with  nominal rated cartridges.  

         One advantage of using "very small particulate" filters, is that  
they remove not only debris, but also parasites, bacteria etc.  To do so, 
however,   you  will  need  to  use  special  sub-micron filters (<than 1 
micron).  This is also called cold sterilizing.  

         The  smaller  the rating of the cartridges, the faster they will 
clog   up,  unless you place several of them in series, starting with the 
highest.  A  series  of 100, then 50, then 25, then 10, then 5, will give 
excellent results, but  is much too expensive to set up for our purposes, 
especially in a "basic" Reef.  

         Whether  or not you need to pre-filter, or fine filter the water 
you  will  be using,often depends on the source of the water itself.  Tap 
water  and  well water, will contain few "visible" particles, but keep in 
mind  that  even  with   good  eye sight, you will not see debris smaller 
than 40-50 microns.   

        Certain  areas  of the country have water that contains consider- 
able   amounts  of  debris,  of  all  forms,  and  it  is  recommended to 
pre-filter the water  if such is your case.  If you buy a filter assembly 
to  do  so  in  a  do-it-yourself  type store, look for "rust and debris" 
canister  filters.   They  usually cost  between 30.00 and 40.00 dollars, 
and replacement cartridges can be bought for around  5.00.  

         Anyone  with  well  water  should pre-filter as well, especially  
because  of   usually  high  amounts  of  undissolved  mineral  and other 
compounds it  contains.  Use the same filter type as if you were removing 
rust and debris from tap  water.  

         Plain  sand filters will remove a fair amount of debris as well, 
and  are  easy to set up.  All you need is an old aquarium, some sand and 
flexible  hose.  The diagram below shows exactly how to set such a filter 
up.  

         Sand Filter for Fine Filtration 

 

 

 

 

 

 

 

 

          A  simpler system yet, would be to use two buckets, one sitting 
on   top  of  the second one.  The first one has a perforated bottom over 
which  plastic  screening  material  is  laid.  This is then covered with 
sand,  or  filter floss, or foam, or some other material that allows fine 
filter-  ing.   The  water goes through  the material in the first bucket 
and  drips,  respectively  flows,  into  the  second   one,   cleaner and 
mechanically  filtered.   This  is, for sure, the least expensive  way to  
set  up  a mechanical filter, but it is not to be considered a low micron  
filter.    It  will  remove  gross  impurities,  and  some finer as well, 
especially if you  use  a thick layer of fine sand.  

         Remember  to rinse the sand after each session.  Let it dry in a 
flat  tray  to prevent the formation of anaerobics.  If you do not let it 
dry,  rinse  it   each   time before you use it.  This is simpler, and is 
probably what most  Hobbyists will do.  

         These  filters  can  be made more efficient by flowing the water  
through  layers  of  progressively  finer, and finer, filtering material.  
The  coarser   layers  remove  the larger material, and the progressively 
smaller ones are removed  as the  water has to go through smaller (finer) 
filtering media.  Both Moe (1982)  and Spotte (1976) give more details on 
such filters.  

 

 

 

 

 

 

         

Remark  :  fine  filters  such as these do not remove dissolved material, 
e.g.    phosphates  and  nitrates.   To  do  this you will need a totally 
different filter,  described later in this section.  
         The  example uses different mesh sizes of gravel and sand, to go  
from  very  coarse  to  very  fine.   Between  uses, the filter should be 
allowed  to   drain.   Before  collecting  water for use in the tank, the 
system  should be run for a  few minutes to remove any possible anaerobic 
contamination.   If  you  wish, you can  place  filter floss between each 
layer to keep them separated, although that is  not really necessary.  

         Activated Carbon filters 

         Moe  (1989)  states that chemical filtration, of which activated  
carbon  is   but  one  example,  is  in  fact  mechanical filtration on a 
molecular  basis.   Chemical filters, indeed, remove "dissolved" material 
at  the molecular level.  The  chemical filters described earlier, remove 
"undissolved" material.  

        A.C., or activated carbon has been around in the hobby for a long  
time.    Unfortunately  my experience with such A.C.  is not good at all, 
except  for a few brands that use the better quality material, especially 
the more expensive  varieties.  

        Plan  on using the latter if you include A.C.  filtration in your  
pre-use treatment of the water.  Don't waste your money on a product that 
may add more undesirable matter to the water, than there already is.  One 
such  compound  frequently added is "phosphate" in many forms.  Phosphate 
is  the cause of many  problems  in the tank, and leads to the appearance 
of  micro-algae,  often  in   uncontrollable quantities, that can quickly 
"ruin"  an  otherwise fine looking aquarium.   These  low quality carbons 
(some  not  even  activated)  should  be  avoided  at all  cost.  Foreign 
imports  too,  should  be  tested  before  use in the tank, as I have had  
several  bad experiences with 2 types, and have lost corals as a result.  

        What  determines  the quality of the carbon, is the source of the  
base  material  to make it, and the fabrication process used.  This gives 
rise to the  existence of the following main types of activated carbon:
         - charcoal 
         - bituminous carbon  
         - lignite carbon         
         - coconut shell carbon (sometimes called vegetable base)
         - mixtures of the above, or "non-descript" origins of carbon
         material, e.  g.  bone, some woods, and others.
       
         Any  type  of  carbon  can  provide excellent results in certain  
specific  applications.   This  is also the reason why every manufacturer 
can  claim that  their carbon is just "the" best.  It turns out, however, 
that  in  aquarium  use  "the"  best  for another application, may not be 
adequate  for  what  we are trying to do,  keeping a vibrant looking reef 
tank.  

        Many  carbons leach phosphate into the water, a fact first point- 
ed  out  to  me by Ken Howery, and further confirmed by personal testing, 
and  the  results of tests made by readers of Marine Reef, the newsletter 
published by Aardvark Press.  

        Because phosphates are at the source of many micro-algae problems  
in  Reef and other tanks, we must at all cost avoid adding more phosphate 
to  the  water.  In fact, we should do all possible to remove PO4 through 
whatever means we can.  

         Ortho-Phosphate,  organic  phosphate, nitrate, ammonia, nitrite,  
phenol, volatile organic compounds, amines, and many other chemicals that 
are  undesirable  can be present in incoming water, whether it be tap, or 
well. Additionally, tap water can often contain high amounts of chlorine, 
and  sometimes   chloramine  and   hexametaphosphate as well.  All of the 
latter  need  to  be  removed,  before  that water can safely be used and 
added to the reef tank (and fish-only tanks as  well of course).  

         Activated  carbon  of good quality will remove most of the above  
compounds   (there are better methods as we shall see a little later) and 
neutralizes   chlorine as well.  It should, therefore, be considered in a 
set  up  to pre-treat  tap and well water, and not overlooked completely.  
There are excellent carbons  available.  

         For  a much more in depth explanation on the differences between 
the    various   forms   of  chemical  filtration,  e.g.   ion  exchange, 
adsorption,  absorption,   molecular  sieves, reverse osmosis, tangential 
flow  filters, and so on, read Moe  (1989) The Marine Aquarium Reference, 
published  by  Green  Turtle  Press,  a  book  all Reef Keeping Hobbyists 
should have, and read.  

         Based  on  what  we  have seen so far, a filter to pre-treat the 
water  could look as follows (there are many variations) : 

         The  2 component unit shown can be improved upon by using a can- 
ister  that can be set up with both carbon, and diatomaceous earth.  Such 
a  canister   will remove whatever A.C.  removes, and will filter down to 
very  low micron levels.   Unfortunately my experiences with diatomaceous 
earth  filters  do not let me  recommend  this set-up.  You could however 
consider  a  System  1*  micron  filter set-up,  with  powdered activated 
carbon.  

 Fill here 

 

 

 

 

      Pump 

  

The  above system pulls water from the vat or old aquarium, circulates it  
through   a  first  and then a second canister, and then back to the vat.  
Water  from  a   well   or tap is used to fill the vat.  The system, once 
switched  on,  can   recirculate  without  the  Hobbyist  having to stand 
around.  Fill one canister with a good  quality activated carbon, and the 
second  one  with  sand,  or  floss,  or a similar  mechanical filtration 
medium.   This simple system will give you better quality  water than you 
would  have  if you did not treat at all, but can still be improved  upon 
as  we shall see in this chapter.  

Such  filters  are  advertised  in  the magazines you read, and are worth  
looking  in  to, as they allow you to combine two filtration steps in one 
unit.   When  you   now   supplement  this  with  the  next  one  that we 
recommend,  you  will  then  have  a  complete pre-filtration system that 
cleans  the  water  more  than adequately for use  in your Reef aquarium.  
Activated  carbon is also used in the system's  filtration, especially to 
control residual ozone.  See previous chapters for more details.            
  
         Molecular Absorption Filters : 

         My favorite form of filtration, because it removes more from the  
water  than activated carbon does, can be visually inspected easily, does 
not leach  anything back into the water, and is cost efficient to boot.  

         Molecular  absorption filters come in pad form, or in discs, and 
are  manufactured,  and sold,by the Poly-Bio-Marine Company through dist- 
ributors   only.  There are, however, so many of them that you should not 
have any problems  finding  "Poly Filters" or discs in your area.  If you 
have not tried them yet, you  definitely should.  

         I  recommended  already  that you use them in your actual system  
filtration  .   Now  I  would  like  you  to  make  them  part  of   your 
pre-filtration  stage  as   well.    This  is  the  last  component of an 
efficient filtration set-up.   

         The  set  up  I recommend for treating water before using it for 
your tank thus comprises three parts : 

         - activated carbon for chlorine removal and some impurities
         - fine filtration for removing particulate matter  
         - molecular absorption for final polishing of the water.  

          The  effluent  from  such  a system is just as good as what you 
would   obtain  from systems costing perhaps 5 to 6 times more, at least.  
Don't  waste  your   money.  In the type of tank we are concerned with in 
this book, you must use  every dollar you are going to spend as wisely as  
possible, so you can include all  the equipment that is recommended for a 
minimum set-up.  

        Because Poly Filters and discs change color as they progressively  
exhaust  their  absorption  capability, it is easy to determine when they 
need  to  be   replaced.   For  pre-filtration purposes, they should last 
quite  some  time.  Many  more months probably, if the water in your area 
is not of all that bad quality to begin with.  

         Reverse Osmosis : 

         Although often seen advertised in Hobby magazines, and indeed an  
efficient  way of purifying the water, I see reverse osmosis on the small 
tank as  overkill, insomuch as the type of R.O.  unit you require to do a 
good job, is expensive, and still the units are slow.  

         In  addition,  reverse osmosis filters waste a lot of water.  At 
best,for  every gallon of filtered water you end up with, you have, cons- 
ervatively,   wasted  another four (more likely 6 or 7).  Reverse osmosis 
filters   are   very  slow,   especially  the  units  that  are  somewhat 
affordable.  The smaller ones produce only  5 to  6 gallons per 24 hours.  

         What is also important to understand, is that the quality of the  
water coming out of the reverse osmosis unit is determined by the quality 
of  the  membrane  used  inside  of  it.   The better the semi- permeable 
membrane  used,  the   better  the quality of the effluent water, but the 
more  expensive the unit will  become.  Good reverse osmosis systems, the 
ones that produce so-called ultra pure  water, can easily cost around one 
thousand  dollars.  Not nearly within the budget  we have planned for the 
small reef tanks discussed in this book.  

         For those interested in what osmosis and reverse osmosis are all  
about,   and  how  the  actual system works, we refer you to the in-depth 
discussion  on   the   subject  by  Moe  (1989)  in  "The Marine Aquarium 
Reference,   Systems  and   Invertebrates",  Green  Turtle  Publications, 
(obtainable from Aardvark Press as well).  

         Reverse Osmosis filtration is efficient in producing high qual-
ity   water,   no doubt about it, but I strongly feel that we do not need 
such a set up in a small reef aquarium set up.  If you already own such a 
filter,  and  if it was  bought for prices around 100 to 200 dollars, you 
probably  do not have all that  good a  unit, at least not of the quality 
just  referred  to.  Check the effluent for  nitrates, and especially for 
phosphates.   Some ortho-phosphate may be left in  the water, and organic 
phosphate will still be there as well.  All is not wasted  however .  

         If  such is the case, the effluent may have to be treated again, 
or  run through a different type of filter.  We suggest that you use Poly 
Filters  ordiscs.  Also, if the reverse osmosis filter you are using lets 
such  compounds   through,   you  should  consider  doing  away  with  it 
altogether and resorting to a less  wasteful and more efficient method of 
pre-filtration,  (see our suggestion later  in this chapter).  Water "is" 
a precious commodity.  Preserve it.          

         De-Ionization : 

         An  excellent  way  of  treating water before it is added to the 
tank.    Very  effective at producing highly purified water.  There are a 
few  problems   associated  with  using  such  a  resin  set-up  however, 
especially at the Hobbyist  level.  

         Resins  only  have  a  limited  ability to remove impurities; to 
clarify  this  means that they can only absorb-adsorb a certain amount of 
them,  and  then  they  become ineffective.  View resins as highly porous 
materials  that have an enormous internal surface area.  When the surface 
area  is filled so to speak, no further impurites can be removed from the 
water, and the resins stop working, and  need to be cleaned.  

        That  is where the problem starts, for most hobbyists anyway.  To  
recharge  resins,  special  treatments  need  to  be performed, and these 
treatments   require the use of rather strong chemicals.  Not everyone is 
prepared  to take the  time to  "re-charge", as it is called, the resins, 
and not everyone is prepared to  handle  the chemicals that are necessary 
to do so, either.  Moreover, a lot of  Hobbyists  who are unfamiliar with 
chemicals, should not use them to begin with.  

        Although  de-ionization  is  very  effective,and  certainly  rec- 
ommendable,  we  prefer  you  to stay away from it if you can.  Resort to 
other methods,  easier to  implement, and not so cumbersome in their use, 
especially  the regeneration part, which requires that you keep chemicals 
around  that can be dangerous if  not used properly, or if they fall into 
the  hands  of  children,  who do not know how  about them, and could get 
seriously  hurt as a result.  I am not saying "do not  use this process", 
but  I  am  definitely alerting you to the potential problems  that surr- 
ound  this  form  of  water  purification.   In  fact,  because  we  sell 
de-ionizers   at  my  company, and in light of what we have just said, we 
offer  a  re-charging  service for resins, so Hobbyists do not have to do 
it themselves.   

         Again, these comments lead us to a simpler filtration set-up,
one  we will  describe  a little later in this chapter, and the one I use 
myself to  prepare water for our tanks.  I sometimes use de-ionization as 
well,  but  only  if  I  need water for very special purposes, e.g.  when 
testing   chemicals   that   are   used  in   products  that  my  company 
manufactures, when I want to be sure the water we  need, does not contain 
any  elements  that  may  interfere  with  the  working  of  the  various 
compounds and products being tested.  

          Resin  filtration can take on many forms.  Details can be found 
in  my   other  books,  and also in our Newsletter Marine Reef, Volume 1, 
Numbers  20 and  21.  Dozens and dozens of different resins exist and are 
manufactured  by  many   companies , Rohm and Haas being perhaps the best 
known  one.   Each  resin,  or  each  set  of resins, as two are normally 
required,  is  meant  to  perform  a  specific  task.   To   do  the job, 
therefore,  you  need  very  specific resins, not just any type.  This is  
often  overlooked by the Hobbyist, or small manufacturer, who is eager to 
have  a  product, and does not invest in the necessary research to end up 
with the right  resin for salt water reef tank applications.  

        Keep  in mind too, that you cannot use de-ionizing resins in salt  
water.  Ionic  competition, especially  from the  compounds that are pre-
sent  in  salt   water   in  great  quantities  such  as  salt  (sodium), 
interferes  with the process.   This coats the outside of the resins very 
quickly,  and  as  a result, they become  totally  "blocked" so to speak, 
and do not perform the task you obtained them for  anymore.  You have, in 
essence,  wasted  your  money,  and  may have a false sense of  security, 
thinking that the resins are in fact cleaning your water.  

         Ultra-Violet Sterilization : 

         UV  sterilizers  have  been  around for quite some time, and are 
meant to kill bacteria and other undesirable very small life forms in the 
water.  As  such,  U  V  sterilizers  can play a role in pre-treating the 
water.   

         Since I have already pointed out that a micron filter of a small  
rating   can  do the same job for you in a much easier fashion, my recom- 
mendation is that, if bacteria, protozoa and parasites are a concern, use 
a  sub-micron  filter.  It  is simple to install, easy to clean and main- 
tain, and inexpensive on top  of it.  

         Ultra-Violet  Sterilization equipment also brings about a set of  
problems  that need to be dealt with for the unit to operate efficiently.  
For   example,  the  water must flow slowly through the housing, and very 
closely  to  the  bulb   itself;  the latter must be jacketed in a quartz 
sleeve,  for  optimum  efficiency,  as quartz glass lets UV rays through.   
The "wattage" of the bulb(s) must be accurately decided upon.  Bulbs need 
to  be  changed  frequently,  and  need to  preferably operate at a temp-
erature  exceeding  100  degrees  Fahrenheit.  If  operated  at the temp-
erature of the tank water, the  bulb  is nowhere near as efficient.  

         For pre-filtering water, this is  not  at  all a  practical sol- 
ution,  in  my  opinion, and I have therefore not included it in the sug-
gested  pre-filtering set-up discussed later.  

         Ozonization as a pre-treatment : 

        If  you treat great amounts of water at one time, and if you have  
cause to believe that bacteria, parasites, protozoa, etc.  may be present 
in the  water,  ozonization is a viable form of pre-filtration.  

         Again,  however,  sub-micronic  filters will do the same job for 
you, and in a simpler and less expensive manner, I believe.  

         If  ozone  is used, you must over-ozonize, and do so to a degree 
that  you can definitely detect residual ozone in the water that is being 
treated.  Use a strong unit.  There are now several choices.  Sander, and 
my own company are  two.  Spotte, in his "Seawater Aquariums" book, gives 
a detailed discussion on  using ozone for this purpose.  

         Dry  and cool the air going into the unit to maximize the amount 
of  ozone  generated, to obtain an efficient kill of small lifeforms, and 
to burn out  (oxidize) organic material that will be present as a result.  

         Ozone  can  be  used  as  an  optional  add-on  to  the system I 
recommend, and  is shown in the diagram later in this chapter.  Make sure 
that all residual  ozone  is removed from the water before it is added to 
the tank.  

         Chemical Additives : 

         In  areas  where  the  water  is highly polluted, some Hobbyists 
resort   to  the  use  of chemicals such as chlorine (in tablets) to pre- 
treat  the  water,   they add permanganates and similar strong oxidizers, 
and  then  filter  the water  through  a sub-micron filter and a chemical 
filter.  

        Although that is certainly a good method, I find it too elaborate  
and  too difficult to implement for the average Hobbyist.  Stay away from  
chemicals, unless you absolutely have to use them.  

        Make  sure too, that they are removed from the water through some  
other  form  of filtration before you use the treated water for the tank.   
Permanganates  will  raise  the  redox  potential  to extremely high, and 
dangerous,  levels. You must therefore let the water stand for quite some 
time and aerate it to  counteract that effect.  It must also be treated.  

         Cold sterilization : 

         We have touched on this in the section on mechanical filtration.  
I   highly  recommend  this  form  of pre-treatment because it is easy to 
install and  does not pose any danger.  It is inexpensive as well.  

         Use  a  filter  material that is rated for less than one micron.  
You   will  thus  remove  not only particulate matter, but also bacteria, 
parasites  and   all  protozoa  that  could  pose  problems for your Reef 
lifeforms.  

         It  is  included  in  the  system that I use myself, and that is  
described a little later in this chapter.  Many types are available, even 
at  your  local  do-it-yourself-store, or hardware supply house.  All you 
need  to  check is  whether the cartridges, or filter bags, are rated for 
less  than  one  micron, or not.   Larger  rated assemblies will not cold 
sterilize.  

         Suggested Set-up for pre-filtration : 

         Based  on  what  you  have read so far, you are probably already 
aware  of what is included in such a system : 

         - an activated carbon stage, mostly to remove chlorine         
         - a sub-micron stage, to remove particulate, bacteria, etc.  
         - a molecular absorption stage, to really polish the water
         - a storage and aeration stage (if necessary) 
         - optional ozonization stage, including dryer and air pump.  

         In  our case the system is piped into a main water line, but you 
can hook the whole assembly up by means of a hose to a faucet.  Mount all 
filters  on   a  small  wooden platform with casters, and you can roll it 
around  easily,  to   where  you will need it.  Clean the system, that is 
flush  it,  before each use, to  remove  the stagnating water.  To do so, 
run  water through the system for a few  minutes.   This will get out all 
water  that is low in oxygen and may have started to  decay,  and provide 
clean and freshly filtered water for your system.  

        Change  the carbon once a month, or sooner, depending on how much  
water  you  treat.   Watch  the  color  of the Poly Filters, or molecular 
absorption  discs, and change them when needed.  

         Flow  water  through  this  system  as  slowly as you can.  This 
ensures   that you get high quality water, free of nitrate, phosphate and 
other contaminants in "one pass", meaning the water has to go through the 
filters only once.  

         Use  old  canister  filters, or special filters such as the ones 
sold   in D. I.Y.  stores, to set the system up.  Connections can be made 
with  hose  barbs,   hose   clamps,  and  flexible acrylic or vinyl hose.  
Never ever run tap water  pressure on the system.  Many canisters are not 
built  to  withstand that kind of "psi".   First close the tap water off, 
and  then the canisters, if a valve is installed  at the end of the line.  
This is very important to remember.   

         Control  the  flow,  meaning  adjust the amount of water flowing  
through the  system, from the beginning of the line, not the end.  If you 
put  an   aquarium type canister under city water pressure, it will burst 
open and you will have  a flood, and may get hurt.  

         You  may  also  wish  to  combine  the three types of filtration  
somewhat.   I  already indicated that powdered activated carbon, and fine 
filtration,  can   be  combined  into  one unit, by using, for example, a 
System  1*  filter.  Add an  extra canister filled with the Poly filters, 
or  molecular  absorption  discs,  in line,  and  you have an inexpensive 
system that will perform very well for you.  

         Rather  than  using a one-pass system such as the one shown, you 
can  also use a  recirculating  system.  Draw water from an old aquarium,
or  any  type  of container, and recirculate it through the filter system 
that  you  have set up,  and  back to the original container.  Let every- 
thing  run  for  10 to 15 minutes, or  less , depending on how much water 
you are in fact treating.  The sequence in which the sub-micronic and the 
molecular absorption  canisters are placed, is sometimes subject to a lot 
of debate.  Some prefer to place the  sub-micronic last.  You decide.  

         This  set-up has worked for me better than what I had anticipat- 
ed,  and  I,  therefore, endorse it completely.  The effluent water is of 
superior quality, at minimal cost, and easy installation.  What else need 
I say.


[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]
3.  Water Additives, Salt : 

        It  is important, as we have seen, to use the right type of water 
to  start  the  aquarium, top-off to compensate for evaporation, and make 
water  changes.   It is also very important that after the tank is up and 
running, that the additives that are needed are added, and that the right 
kind of salt is used to prepare the water for the Reef tank.  

         If  we  are  going to dispense with fancy equipment, and we are, 
then let's  at least make sure that we cover all other required steps, to 
improve  the  water quality, and do so with the best products we can get.  
Don't  economize  in the wrong areas !  If you try to, you will be making 
the wrong decisions, and your aquarium and your animals will suffer.  

         Reef Aquarium Salt :
         You  will  be  using salt for as long as you keep your tank, and 
salt  can  make up a large portion of the money you will need to spend on 
the aquarium.  This  leads many Hobbyists to buy the cheapest salt avail- 
able.  That is, in my opinion, a real big mistake.  

         Scuba  divers  amongst  you will easily understand the following 
analogy :  when you refill your air tanks, you want the best and cleanest 
"air"  you  can get .  Your life depends on it, doesn't it ?  Your corals 
and fish feel the same about  the water and the salt you use.  Their life 
depends  on it.  So use the best quality you can get; your tank will look 
better,  and  you  will  have far less problems.   It would cost you much 
more  to  replace  fish and invertebrates, than what you can save on salt 
and additives.  

         Fish-only  tank  salt  is  of excellent quality, but may contain 
impurities   that  you  do not want in your "Reef" tank.  I am especially 
talking  about  nitrates  and  phosphates .  I cannot give evaluations of 
individual  salts  in a book, as I  am sure you realize.  I can, however, 
give you a test that you can use to determine whether or not the salt you 
are  now  using, or are planning to use, fits the  quality picture I just 
indicated : 

         - mix up a batch of water with that salt, 
         - let the mixture stand for a few hours, 
         - stir once in a while, or run an airstone in the mixture,
         - test for nitrates and phosphates, 
         - if you find any of either, try a different salt.  

         If  you  find  that  the salt you are now using, or plan to use, 
contains  impurities  such as nitrate and phosphate, my recommendation is 
that you try another salt.  Why add compounds that you will have to go to 
great  length  to  remove ?  I  ask you, why ?  Especially since removing 
them can be quite difficult and an expensive proposition on top of it.  

         For obvious reasons we use Tech-Reef-Salt, an ultra pure mixture 
of all the elements needed, and trace elements required.  You may wish to 
alternate  its   use with another less expensive salt.  I personally like 
Hawaiian  Marine  Mix  a lot, but there are other fine salts that fit the 
picture as well.  

         Alternatively,  use a mixture that you make up yourself, of Tech 
Salt and another salt, in a certain proportion.  For example, a mix of 25 
(resp.  33) per cent of one and 75 (resp.  67) percent of another one, is 
an  excellent  solution,   will improve the overall quality, and will not 
cost a lot more than what you are  doing now.  

         Mix  the salt and the water several hours before you plan to use 
it.   This   will  allow  the  mixture  to  stabilize itself, and all the 
components of the salt  to dissolve properly.  In this fashion your redox 
potential  will  also  not  be  affected  as  much when you change water.  
Indeed,  raw water (just prepared) can alter  your redox potential easily 
by  more  than  100 millivolt.  I have seen it happen many times.  If you 
prepare  the  new  water  beforehand, and let the solution sit for  a few 
hours, while aerating it, the effect will not be as drastic.  

         If  you  would  like  to try Tech-Reef-Salt, send us a check for 
fifteen  dollars,  including  freight and handling, before Sep.  30, 1990 
and a note asking for  a small sample, enough for a 10 gallon water prep- 
aration,  and we will gladly send it to you.  This is genuinely a special 
salt,  made  to the highest specifications I can expect a manufacturer to 
hold himself to in making a product for us.  No  phone orders please.  No 
cash on delivery either.  Only by mail.  Valid only in Continental United 
States.  

         Trace Elements :  
         There  are  many theories about adding trace elements.  Some say 
that  the  amount  contained in the salts you use is plenty, and that you 
therefore  do  not  need to supplement.  That does not make much sense to 
me.   Skimmers,  ozonizers,  and  the lifeforms in the tank, continuously 
remove trace elements, especially the algae, both micro and macro.  

         Moreover,  trace  elements are removed in unequal amounts.  Some 
disappear   faster  from  the water than others.  Which ones are depleted 
more,  depends  on  many  factors, including what type of macro-algae you 
grow,  and  what type of invertebrates you keep.  Peter Wilkens, the well 
known German author has written extensively about this, even to the point 
where  his experimental findings totally contradict what some avant garde 
German manufacturers say.  

         It  makes  a  lot  of  sense,  therefore,  to use an additive to 
replenish such  trace elements from time to time.  More frequently if you 
skim  heavily,  e.g.   when  using  the newer Venturi valve operated foam 
fractionators, or efficient columnar ones, operated with ozone.  

         How  much  of  an additive you should use depends on the type of 
additive  you  have bought.  Follow the directions of the manufacturer in 
this  respect.   Be aware, too, that most of their recommendations are on 
the conservative side.  

         Because there are no "tests" available for trace elements, no
one  can  actually  check  their  levels.   The recommendations made are, 
therefore, based on personal experiences and the experience of other well 
known Hobbyists and researchers.  

         Moe  (1989)  expounds  on  the  subject  in  The Marine Aquarium 
Reference,  his   new  book, referred to several times already.  Wilkens, 
known  to  most  of you, is  pretty clear about having to add elements to 
his  tanks,  to  maintain  invertebrate s and corals alive and in vibrant 
condition.   Many  others  before  me  have  said  so   too.  This is not 
something  new,  it has been around for a long time, just not highlighted 
often enough.         

         All  the  recommendations  made  in this book, and others I have 
written,  are  not  meant to make you spend more money yet, but are truly 
meant  to  allow you to keep a Reef tank that will give you pleasure, and 
where  your  investment  in animal life remains alive for long periods of 
time.   Much  longer  than  what  many  of  you  have been accustomed to, 
especially since we are running a basic system.   

         The  cost of a few good additives, this one and others mentioned 
later,  is  far  less,  than  continuously  having  to  buy new anemones, 
elegance  corals,  sunflower corals, etc.  Replacing animals and fish can 
get  very  very  expensive.   Do a little preventative investing, and you 
will  fare  a  lot  better  in  the long run.  And besides, you will do a 
little  too  to preserve the reefs, and reduce collecting  of the animals 
you like to keep.  

         Vitamins :  
         If  you were able to duplicate the food chain that exists around 
the  Reef,  you  would  obviously  not  need  any  additives  whatsoever, 
including vitamins.  You  and I know that we cannot do that, yet, anyway.  

         Vitamins  are  an important constituent of the foods that corals 
and  invertebrates  live off around real reefs.  Different lifeforms have 
different  requirements,  not  all of them well known in fact.  Many have 
been identified, many are still not documented, or only partially so.  

         Mixtures  of  vitamins,  amino acids, micro-nutrients, pigments, 
organic  elements,  and  other  compounds  that are part of a normal food 
chain, are marketed.   I suggest that you use them.  Add them directly to 
the  tank,  or better perhaps, mix them with the food before you actually 
add  the  food  to the reef aquarium.  This is especially so if you use a 
good foam fractionator and an ozonizer.  And many  of you are.  

        There are several brands that are widely available nationwide and 
in  Canada.   Vita-Trace, Coralife and Vita-Chem are but the better known 
ones.  

         Be  careful  not  to  add too many vitamins at once if you use a 
protein  skimmer.   Some  brands  make the protein foam fractionator skim 
more  strongly. As with any additive, add it regularly, in small amounts.  
Best  is  to  add  it  by means of  a drip system, in diluted form, or by 
means  of  a  dosing  pump.   Thiel  (1989)  describes  this in detail in 
Advanced  Reef  Keeping  Made Simple (I), and also in The Marine Fish and 
Invert Reef Aquarium, his other book, all published by Aardvark Press.  

         Many  foods  already  contain  additional vitamins.  Such is the
case of, for  example, the Coralife line of foods, Reef Smack Melange, my 
own  company's  dry food, and others as well.  Does this allow you not to 
use vitamin supplements?  That is a very hard question to answer, indeed.  
My  suggestion  is  that you use both  food and vitamins made by the same 
manufacturer, and then follow the directions  they provide.  Again, and I 
know  I  am  repeating  myself,  protein  skimmers  and ozone remove many 
elements from the water, including vitamins.  

        Does  it pay to change vitamin brand from time to time ?  No con- 
clusive  data  on such switches are available as far as I can tell, and I 
have, personally,  not been able to notice any difference in my own tanks 
when  doing  so.  Get a good  brand and stick with it.  Use it regularly, 
and  increase  the  recommended dosage  somewhat if you are strongly ozo- 
nizing.   You  can not overdose any way.  Look for  brands that contain a 
wide range of all known vitamins.  Buy only products that look fresh when 
you  get  them,  and smell like vitamins.  Stick with established brands, 
since they have been around for a few years, they obviously must be doing 
something right !             

         Special Additives : 
         A  number of specialty additives are available.  These include : 
Iodine,  KSM,  and  Liquid Gold, all from my own company, and a number of 
nutrient  formulas   from  Coralife,  e.g.  Appetite stimulant, Micro nu- 
trients and Calcium supplement.   I know of no other two companies offer- 
ing  such a wide assortment of specialized  supplements, other than trace 
elements and bio-elements.  

        Are they necessary? Well, if they were not, I would not have dev- 
eloped  them,  and I would not have spent money on the research necessary 
to  do so.  Additionally selling merchandise that is not "necessary" does 
not  reflect well on a company"s image, and products that are of no value 
to  the  Hobbyist  would not be around for long, as no one would buy them 
for any length of time.  Hopefully that answers your questions.  

         The  same  reasoning applies to products from companies such as, 
for  example,  Coralife.  Why would they stake their reputation and money 
to  bring  you products that are of no value ?  Obviously they would not.  
It would be totally uneconomical to do so !  

        So  yes, such additives are important, but not for every one.  It 
all  depends  what kind of corals and invertebrates you keep, and whether 
or not you have  a full-fledged reef tank.  If you do, I strongly suggest 
that  you consider  using them.  Again, the cost of adding a few drops of 
a supplement from time to  time, may save you lots of dollars in the long 
run,  not  to  speak  of  having a healthier and better looking tank, and 
keeping  the  lifeforms  you  have  now  in your  aquarium alive for much 
longer, and growing.  

         A  Reef  tank  is  an  aquarium where the orientation is towards 
corals,  anemones,  polyps  of  many  kinds,  mushrooms, and such type of 
lifeforms,  supplemented,   of  course,  with  fish.   The main thrust is 
invertebrates.  A tank with many fish  and 2 or 3 anemones will obviously 
not have the same requirements.  

         Iodine  is a compound that is required by many higher algae, and 
by  many   invertebrates.  Foam fractionation removes Iodine quickly from 
the  water,  and  it   needs to be replaced as a result.  P.  Wilkens, G.  
Hueckstedt,  and others pointed  this out years ago.  Moe (1989) recently 
reintroduced  the  concept in his new book .  Use Iodine supplements with 
care.   Iodine is a strongly redox potential increasing compound.  Follow 
the directions carefully.  But use it, it is a very beneficial additive.  

         KSM  is  an  additive I developed for my own use in keeping hard 
corals,  especially  Elegance.   Often these corals literally come out of 
their  hard  skeleton.    Hueckstedt, many years ago, hinted at a lack of 
certain  trace  elements,and P. Wilkens tested until he had evidence that 
the missing elements were strontium and molybdenum.  KSM provides both in 
an easy to use mixture.    

         Use  it  if  you  keep _Catalaphylia plicata_ (jardinei), better 
known  as  Elegance  Corals, _Gonoporia_ species corals, also known under 
names  such  as  Sunflower,   Moon, Flower Pot corals (and others still), 
_Euphyllia_  corals  or  plate  corals,  and other types of hard skeleton 
corals.    If  you  only  keep  anemones,  tube  worms,  mushroom  corals 
(_Actinodiscus_ sp.), and corals without a hard skeleton, you do not need 
KSM.   If you fall in the other category, do yourself a favor, and invest 
in  a few ounces every month or so.  Don't buy large quantities, you only 
need ounces.  

        Micro-Nutrients  are a definite requirement in every Reef.  Since 
they  are  the ones present in the smallest quantities, they are also the 
first  ones  to  be  depleted.  Will you see your Corals perk up when you 
use  them  ?   Probably  not, but you will find that in the long run your 
Reef will do much better if you do use  them.  I do.  The product is hard 
to  manufacture, and the only company at the time of this writing who had 
it  available  was Coralife, which of course also markets many other Reef 
specific products.  

         Liquid  Gold  : this is a very special additive, and one that is 
very  close  to  me.  I developed it over the last 5 years, and finalised 
its  formula  about  1   year  ago.  I use it every day, and would not do 
without  it.  I call it by that catchy name because I really believe that 
it does special things for the animals in my Reef set-ups.   

         "Liquid  Gold" contains not only nutrients, and can therefore be 
considered  a food, but it also contains selective amounts of trace elem- 
ents,  small  amounts  of  4  vitamins that I consider very important for 
corals  and  invertebrates,  free  amino  acids, fatty acids, pigments, a 
selected  number  of  organic  compounds  necessary to filter feeders and 
corals  of  amongst  other  the  _Actinodiscus_ types, iodine, strontium, 
molybdenum, carbodydrate, saccharides, polysaccharides, organic  forms of 
metals  such  as  gold, iron and silver, and many many others yet.  It is  
truly  a  super-mixture  of "all" the elements and compounds, organic and 
inorganic  ,  that  available  literature  has  demonstrated  to  be both 
necessary  and  beneficial  for corals, invertebrates and other lifeforms 
kept  in Reef Aquariums.  I unequivocally, and without hesitation, highly 
recommend it to you too.   

        You  do not need much of it, so don't be alarmed by its price.  I 
could,  of  course, sell it in diluted form, make you use more of it, and 
charge  less  per  container.  You would then go through more containers.  
The  end  result, cost-wise,  would still be the same.  It is, therefore, 
sold in 2 oz dropper bottles that are easy to use, and in 4 oz refills.   

         Appetite  Stimulant  from  Coralife  is another additive that is 
"special",   insomuch  as  they  are the only ones making such a product.  
Use it according to their instructions and you will be impressed with the 
results  you  obtain.  Feeding  is triggered by certain stimuli, and that 
is exactly what this product does.  It  promotes feeding.  

         Ridalgex : a water additive by Thiel-Aqua-Tech for those Hobby-
ists  who  have  difficulty  with  their  water  chemistry, and who, as a 
result, experience high  amounts of micro-algae and slime algae growth in 
their  tanks.   Although  better  water  chemistry would take care of the 
problem,  when  such is not practical or not  possible, Ridalgex will rid 
the  tank  of undesirable slime, hair and other micro-algae.  It increas- 
es  the  time  between cleaning the glass (or acrylic) as well.  Safe for 
reef  tanks,  and effective.  Sold in 1 ounce dropper bottles.  This is a 
product  to  be used when needed, e.g.  when normal procedures do not rid 
the aquarium of red, slime, brownish and other type of algae.   

         Micro-Algae Control : a product similar to the one just mention-
ed  above,  to  control the growth of all forms of micro-algae, including 
slime,  hair, and  others, on rocks, glass, and in the aquarium.  This is 
one  is by Coralife, a very  reputable company that brings you many other 
Reef  and  Salt  water  tank  products.    Safe  for reef tanks, and very 
effective.   Sold  in  Coralife's  usual large bottles  with dropper top.  
This  product,  based  on the instructions, is geared towards maintenance 
and prevention.            
         KH Generator Fluid : any tank containing hard corals needs to
 be  run at  a relatively high carbonate hardness.  Thiel (1989) explains 
the  reasons  for  this  in  detail in both his books on Reef Tanks : The 
Marine  Fish  and Invert Reef, and Advanced Reef Keeping Made Simple (I).  
Many other authors concur.   

         Suggested  levels are between 12 and 18 dKH, or between 4.28 and 
6.43  meq  /liter.   This  is much higher than the carbonate hardness one 
gets  from  using  aquarium  salts,  obviating the need for a supplement.  
Peter  Wilkens (1973) suggest levels that are even higher : dKH 15 to 20.  
Wilkens (1973) and Thiel (1989) both suggest the addition of "kalkwasser" 
or  limewater,  over  and  above  the  use  of  carbonate and bicarbonate 
additives.   More  references on how to do this exactly, can  be found in 
"Marine Reef" the newsletter.  

         Tablets,  and powders, are available from several manufacturers, 
e.g.   Instant  Ocean  (Aquarium  Systems).   Fluids  are  available from 
Thiel-Aqua-Tech  and  from  Coralife as well.  You can even make your own 
buffers  if you take the time to do so, and can get the chemicals needed.  
Moe  (1989) gives a suggested, and totally safe, formula based on the use 
of sodium ash and sodium bicarbonate, a two component mixture.  

        The reason I recommend liquids, and have been doing so for years,  
rather  than  tablets,  is  that  the  latter  may make your skimmer foam 
excessively,  resulting  in  floods.   Liquids  do  not  need  to contain 
binders, and can therefore be added safely, without having to worry about 
your protein skimmer.    

         Be  aware, too, that some manufacturers try to sell you straight 
baking  soda  (sodium  bicarbonate)  for a hefty price.  Although that is 
obviously one of the necessary constituents of a good KH generator, it is 
only  one  of  at  least  4  compounds that should be present.  Don't pay 
premium  prices for a product that is not complete, even if it comes in a 
nice  container,  has  an appealing color, and may come from abroad.  You 
can  buy  pure  baking soda for pennies at your local supermarket, and it 
will not even contain binders that make your skimmer foam excessively, as 
some of the products referred to above do.   

         As  a  general  remark  :  Colored  products are not necessarily 
"better",  indeed,  color is often a harmless dye that is added, and that 
dye does not enhance the efficiency of the product, it just makes it look 
better.  Granted, the dyes used that we looked at, are safe.  

         A  good  KH  generator  should  not  only  raise  your  carbonate 
hardness,  but it should keep it there for quite some time.  How long, is 
hard to state because it depends on the biological load of the tank.  The 
higher  that  biological load, the more organic and other acidity will be 
present,  and  the  faster  the carbonate  hardness will drop.  Carbonate 
hardness  is  also a factor of how many algae, both  micro and macro, are 
growing  in the tank.  Algae require carbon dioxide because of the carbon 
present in it.   

         If  they cannot find free carbon dioxide, or if they cannot find 
enough  free  CO2,  they remove the carbon from the the bi-carbonates and 
carbonates   present   in   the   water.    At   the   extreme,  biogenic 
decalcification  takes  place,  and a white powdery dust covers the rocks 
and  the glass.  This, of course, reduces the carbonate hardness greatly.  
Even  without biogenic decalcification, carbonate hardness is reduced and 
needs  to be adjusted by the addition of an additive.  Adding CO2  to the 
tank,  does  not do away with the need to adjust the KH, to the contrary,  
it  may  increase  it (Thiel, 1988).  This is described in detail in "The 
Marine  Fish  and Invert Reef Aquarium" and also in some issues of Marine 
Reef,  Aardvark Press' newsletter, of which bound issues are available as 
well.  

        KMnO4 : Hobbyists who do not use ozone, and some who do, but have 
a  need   for  more  oxidative power in the water, use a strongly diluted 
solution  of  Potassium permanganate, and add it drop-wise to the tank or 
filter sump (best).   

         The  use  of  oxidizers on a more generalized basis, is a rather 
recent  occurance,  and needs careful watching.  Several German sources I 
deal  with  find  it  very  helpful,  providing the user has the maturity 
necessary  to deal with a chemical where the difference between the right 
dose, and too much, is not all that large.  

         KMnO4  is  a strong oxidizer and not a chemical you want to play 
around  with, unless you know exactly what you are doing.  It can, as far 
as  I  have  been  able to determine, be added safely to an aquarium, for 
brief  periods of time, and  intermittently.  If you are new to this type 
of a chemical compound, best is to use the liquid form.  

         What  is  important,  is that you buy the product from a company 
that  you  can  rely  on to have tested the strength of the solution they 
sell.   It  should  never  in  my  opinion,  exceed  550 millivolt of ORP 
(redox),  and  should  be added to your tank only in the slow drip method 
fashion.   If the product is too strong, after  you test it with your own 
redox  meter,  further dilutions are necessary, and must be done by using 
distilled  (U.S.P.  purified) water only.  In fact, water purer  than USP 
purified  would  be even better.  Unless you are really familiar with how  
this  works,  do  not  use  KMnO4  until  someone  who does has carefully 
explained to you how to go about adding it.  

         Hydrogen  Peroxide  :  an  absolute  no  for reef tanks.  It can 
quickly raise the oxygen content of the water, but it can also do so much 
damage  so  quickly,  that  we ask you to not use it at all.  Wilkens and 
Hueckstedt  have both described  methods of adding it safely.  Experience 
shows,  however, that hobbyists usually overdose, and that all corals and 
invertebrates greatly suffer, to the point where they will be lost.  

         If  you  must use hydrogen peroxide, you should do so only after 
you  have  consulted  with  someone  who  has done so before you, and has 
experience with strengths and dosages.  I know of no product in the hobby 
using hydrogen peroxide safely as an additive.  

        Sodium perborate : same remarks as for hydrogen peroxide.  Please 
do not  use this chemical either.  It works fine in fish-only tanks, just 
as  peroxide  does,  but in Reef aquariums too many disastrous situations 
have been reported by hobbyists who did not really heed the instructions.  
One  can  even find mixtures of  the above two chemicals.  Stay away from 
those  too.   The  latter are usually sold  as products that will quickly 
increase the amount of dissolved oxygen in the water.  

          Kalkwasser  :  touched  upon  briefly  early  in  this  chapter, 
kalkwasser  is   a  mixture  that is used to increase not the "carbonate" 
hardness of the water, but the "calcium" hardness.  

         It is a very important additive for every hobbyist who maintains 
hard corals, as the latter use the elements in the kalkwasser to grow and 
multiply.   The   type  of  corals referred to include, for example, Meat 
coral,  Sunflower  coral, Elegance coral, Bubble coral, and similar ones.  
All  coralline algae benefit from  the addition of kalkwasser as well, of 
course.  

        Kalkwasser, or Limewater, has been advocated for invertebrate and 
coral  aquariums since the days of Guido Hueckstedt and Peter Wilkens, in 
the  60's  and   70's,  in Germany, but nobody seems to have given it the 
importance  it  deserves,   when  the  Reef Aquarium became a fact in the 
United States and Canada.   

        George Smit's constant reference to the need for having layers of 
"calcite"  in  the  water,  under  the  trickle filter, may have been the 
closest  to  suggesting  that calcium carbonate, and calcium as such, are 
important  in  a  Reef  Aquarium.   He  did not go as far, however, as to 
suggest  the  addition  of  some  form of calcium compound in a dissolved 
manner.  

         Adding Kalkwasser is, in my opinion, just as important as adding 
salt,  or maintaining the right pH, temperature, etc.  It is certainly as 
important as adding the right kind of supplements, e.g.  Iodine, KSM, and 
others described in this chapter.   

         At  Thiel-Aqua-Tech  we  add  it every day, and have done so for 
years, with very positive results for all the corals we keep, and we keep 
many  types.  My company, therefore, also sells it to the discerning Hob- 
byist.   We use USP grade calcium hydroxide and triple distilled water in 
its  preparation, and run lab grade  carbon dioxide through it, to adjust 
the  pH.   Marine  Reef,  our  newsletter,  recently  carried  an article 
describing  how  you can prepare it yourself.  It is not easy, but it can 
be  done, as long as you have a source for the chemicals, and already use 
carbon dioxide on your system.                   
         X-Nitrate  :   a granular compound sold in several sizes that is 
placed  somewhere  in  the  water  flow  to  remove  nitrates,  and  some 
phosphates,  in  an  aerobic manner.  Aerobically means that this product 
does so in the presence of oxygen.   It is, therefore, much easier to use 
than  the  so-called  "denitrators" that are  available, and that work on 
the  semi anaerobic principle (facultatively aerobic-anaerobic bacteria), 
with the addition of a carbon source (the nutrient).  

        X-nitrate is a natural compound, must be rinsed well before it is 
used,   and  cannot  be  regenerated once it has exhausted its absorption 
ability.   It  is no t a zeolite.  For Hobbyists whose tanks contain high 
amounts  of nitrate, for what ever reason, this product is a very welcome 
addition  to  the  reef  product array.   You can, for instance, test for 
nitrates  with  the  Route  4 Marine Technology low  range nitrate test .  
This  will  give you a good indication as to when you should  replace the 
product.   Incidentally,  that  same company markets a full range of Reef 
water tests.  

         Nitrate-Phosphate Control : Coralife also markets a product that 
removes nitrate and phosphate from the water.  Again the compound must be 
placed in the  water flow.  As the water contacts the product, the latter 
removes nitrates and  phosphates.   

        Low  nitrates and low phosphates are important in reef aquariums, 
because  their levels affect the appearance of the invertebrates that you 
keep,  and also  affect the amount and type of micro-algae that will grow 
in  the  aquarium.   Levels that are too high make the tank look dull and 
not appealling at all.    
      
         - Conclusion : 

         We  reviewed  most  of the additives that you should use on your 
reef  aquarium.  There are probably still others, and newer ones may have 
appeared by the time your read this book.  

         Refer to an authoritative source of information to keep yourself 
up-to-date  on the latest developments in Reef Aquarium keeping, the most 
challenging  part  of  the  marine  hobby,  but  also the one where water 
quality  is  the most important, in terms of the type of success that you 
can expect.  

         Moreover, because the Hobby is still so "young" in this country, 
a  lot  of  misinformation is unfortunately circulated, not willingly, of 
course,  but because many shops and hobbyists have little experience that 
can be backed up with  notes, time, empyric evidence, etc.  

         There  are  several  excellent magazines dedicated to the hobby.  
Some  are  more orientated to marine environments than others.  We highly 
recommend  Freshwater  and Marine Aquarium, better known to some as FAMA, 
and,  of  course,  there  is our own newsletter : Marine Reef, that deals 
with  nothing  but reef aquarium technology and the animals that you can, 
or may already be, keeping in your tank.   

         It  is  now in its second year of publication, and all issues of 
the first  year, numbered 1 through 17, are available in soft bound form.  
Call Aardvark Press for details if you are interested.  Signed, numbered, 
hardbound editions are  available as well.  
4.  Lighting for the Reef Tank 

         Introduction : 

         If  there still is a controversial subject in Reef Keeping, this 
is it.  Thousands upon thousands of words have been written, recommending 
just  about every type of light that is possibly available on the market.  
This  includes  most types of fluorescent fixtures and tube combinations, 
and  many  other  forms  of lighting, especially high intensity discharge 
ones, as well as a whole number of hybrid systems.  

         I  certainly  do  not have all the answers here either, but I do 
know what  has worked for me for many years, ever since I first saw metal 
halide  lights,  in   Germany,  over  Reef  aquariums in Pet shops and at 
Hobbyist's homes, over their reef aquariums.  

         Their  tanks looked so much better than what I was accustomed to 
see that, when I represented a German company in this country, I was most 
enthused  about  bringing  that type of lighting into the market place in 
the  United  States  and Canada.  I experimented with these metal halides 
(Osram  Power Stars at that time),  and had the same type of success over 
my  own  aquariums  as  the  tanks that I had  seen overseas, in Germany, 
France and England.  

        Soon thereafter, a foresighted American manufacturer, Omer Dersom 
of  Energy Savers Unlimited, took a large commercial risk, and decided to 
offer  metal  halide  lighting  to  the  Hobbyist at much more affordable 
prices  than  what  they  had   been  available for up to then.  First he 
introduced  4300  K  degree  bulbs,  and  recently 5500 K degree Daylight 
(blue-white) ones.  His strategy obviously worked, and such metal halides 
are now the norm of every discriminating Hobbyist I know.  

         Still,  some resellers in this country advocate a different form 
of  lighting, and put much too great an importance, I feel, on the use of  
actinic lights, often, if not always, mixed with other fluorescent tubes.  
To me, there is no question at all, that time will prove me right.  Metal 
halide  lighting  is  the  only  safe way to go, and where you should put 
your money if you are in the market for lighting for a Reef tank.  

        Do not misunderstand me, even though you can keep quite nice reef 
aquariums  with  certain  types  of fluorescent lights, providing you use 
enough of them;  the difference between such tanks, and similar tanks run 
with metal halide lights, is like day and night.  If fluorescent tubes is 
what  you  use  now, see later in  this chapter for suggestions on how to 
improve  your  existing  set  up,  by  either   changing  the  bulbs,  or 
increasing respectively their numbers and/or output.  

         That  metal  halide  lighting  is the only way to go, is quite a 
strong  statement,  but  one that I believe to be absolutely correct.  My 
own experience, and  that of many hobbyists I know, is plenty of evidence 
to support that statement.   Tanks lighted with metal halides, especially 
the daylight types (5500K), just  do a great deal better than other tanks 
I  have  seen.   You  can  find  evidence  of  that  in  my new series of 
videotapes  dealing  with   "The Reef Aquarium Corals and Inverts : Types 
and Care" Parts 1 to 3, available from Aardvark Press.  

         Aquariums  lighted with fluorescent tubes, just do not allow the 
corals and invertebrates to develop the way they do in tanks lighted with 
metal halides,  and high Kelvin degree mercury vapors (clear types).  The 
tanks  may  look  nice, and some hard corals and some mushroom corals may 
show  vivid  colors,  but  at  the  sacrifice  of their physical size and 
appearance.  To me, at least, that is not an  acceptable trade-off.  

         The  only  caveat  when using metal halide lighting, is that you 
must  use  the  right kind of metal halide bulb.  If you do not, you will 
not  get  the  results   that I can otherwise guarantee you.  The halides 
must  be  of the "high intensity discharge" type, meaning you will need a 
transformer box with them.   

         Don't  be afraid though, when you buy such a lighting set-up you 
obtain all the parts needed in one purchase.  You will not have to go out 
and buy any other parts separately.  Keep this remark in mind, indeed, if 
you  are offered a so-called metal halide that does not require a ballast 
(transformer)  and  that  you plug directly into the wall outlet, you are 
being  offered  the  wrong  light  !   Those  are mostly Tungsten halogen 
quartz lights, which give off a lot of light, but also very yellow light, 
not suitable for the reef tank.  

         Metal Halide Lighting and Corals : 

         Ever  since  I  wrote "The Marine Fish and Invert Reef Aquarium" 
book,  hundreds  and  hundreds  of Hobbyists have called to ask questions 
about  lighting,  and   also why I am so adamant about using metal halide 
bulbs.   The  reason is very simple: because they allow me to keep a Reef 
tank  with  invertebrates  that open to the fullest I have ever seen, and 
keep  them  that  way  for  the longest of times, not  just a few days or 
weeks.  Anyone who has seen my main show tanks can attest to  that.  

        Visualize  purple mushrooms (_Actinodiscus_ sp. and _Actinodiscus 
sharonii_)  that are about 1/4 inch when they are closed, open to about 3 
1/2  to  4  inches  when  fully  open under metal halide 5500 K Coralife* 
bulbs.   

         Visualize  the same purple _Actinodiscus_ species mushrooms lift 
off the rocks on which they are, so you can see a stem underneath them of 
about  3/8  to  1/2   an inch in diameter, and well over an inch long.  I 
have never seen that happen  in a tank with fluorescent tubes to a degree 
that  frequent  as it happens in aquariums with MH 5500K bulbs.  The size 
coloring,  and  shape  of  _Actinodiscus sharonii_ is only one example of 
what can be achieved with such bulbs over a Reef aquarium.  

        Another  good example of what metal halides can do for corals, is 
the  coral  _Catalaphyllia jardinei_, sometimes referred to as plicata as 
well  (common names  Elegance, or Elegant).  Although they may stretch to 
quite  a  large size under strong fluorescent lighting, you will see them 
"grow"  to  about  1.5 to 2 times that  size under metal halide lighting, 
combined, of course, with good water quality  (redox of 300 mv or more in 
the  aquarium  itself).   Some  specimens in my tank are  literally huge, 
especially  considering  that  the  hard  part underneath in only about 5 
inches long and 3/4 of an inch wide, and is not branched.  

        Elephant  ear corals, _Discosoma_ types, which normally stay flat 
and  close  to the rock to which they are attached, open up wide, stretch 
and  curl at the edges, even when they are not feeding, and become larger 
than  you  have  ever  seen   them  under  fluorscent lighting, even when 
supplemented  with special blue and green bulbs.  Elephant ear corals are 
delicate corals, feeding on both live foods and extracting nutrients from 
the water and from photosynthesis.   

         Many  anemones, e.g.  Clownfish anemones, of the "ritteri" type, 
migrate upwards closer to the metal halide lights, proof, obviously, that 
they find it beneficial.  Additionally, the ones we have in the home show 
tank, do not lose their colors.  I keep 2 large ones, and both are a good 
15  inches  across  when  they  open  up completely a few hours after the 
lights  have been on.  The noteworthy fact , of course, is that they were 
only about half that size when I originally placed them in that tank.  

         _Euphyllia  ancora_,  the  coral  with  the kidney shaped end of 
tentacles  (as   opposed  to  the  Tee-shaped  end of hammer head corals, 
_Euphyllia cristata_), stretches its tentacles to a length of possibly as 
much  as  6  inches.  In the same tank _Euphyllia glabrescens_, the coral 
with  the  whitish  round  ended tentacles increases in shape to be point 
where it bulges out of the hard skeleton.  

         I  could  go  on  and on, but I am sure that you have gotten the 
point I am  trying to make.  Although other forms of lighting may be ade- 
quate, metal halides,  of the high intensity discharge type, 5500 K, give 
better results in Reef Tanks .  

         It  has  also been said that metal halides "burn" corals !  That 
erroneous   rumor  is  now  heard  many  times in discussions about light 
between  Hobbyists  !   Be   aware that some companies that we think were 
responsible  for  that  statement,  now  sell metal halides imported from 
another  country,  whereas before they were touting, over and over again, 
the benefits of actinic light.   

         Metal  halide lights, used properly, with UV shields, if so rec- 
ommended,   do  not harm corals.  Not a bit.  The sun gives off much more 
UV than even the strongest metal halides can, and beats on the coral reef 
day in, and day out, granted with the water as a partial shield.  

         Actinic  light  can,  under certain circumstances be beneficial, 
especially if the other lights used in conjunction with it, are not of as 
full  a  spectrum  as  they  should.  In this respect be aware that Osram 
bulbs,  as  now sold in this country, have a spectrum of only 4300 K, not 
nearly as good, for our purpose, as the newer 5500 K metal halides.  4300 
Kelvin  degrees is very good, but 5500 K is much better.  The experiences 
of others who have used them, and my own, are proof  of that.  

          Actinic  light  will,  often,  give  the  tank  an  eerie  look, 
especially  if you use several strong ones.  This distorts the appearance 
of colors, and makes animals look unnatural.  Metal halides, because they 
are  a  much  more  "complete" light source, do not.  In fact, the 5500 K 
proprietary  Coralife bulb, is rated as a daylight bulb, meaning that you 
will  perceive  the  colors of the animals in your tank as "true" colors.  
On  paper  that  may  sound  unimportant,  but  in reality, looking at an 
aquarium  that  does  not look "real" is very strange for anyone visiting  
your house.     

         The  photograph  on the cover of this book was taken around 3:00 
pm,  while  700 watt of metal halide lights of the 5500 K type were burn- 
ing for several hours.  Those purple mushrooms look a lot better, I feel, 
than some others I have seen in photographs.  

         How  much light intensity should you install?  A lot if you can.  
The  minimum  I  recommend  is 2.5 watt per gallon of water in your tank.  
More  if  you  want better results.  Over a 55 gallon tank you can easily 
place  175 watts or more of metal halide lighting.  I have 700 watts over 
a 135 in my house, and all are 5500 K  metal halide bulbs.  

         Availability of lights, and their respective wattage, may make
it necessary for you to adjust somewhat upward or somewhat downwards, but 
use 2.5 to 5 watt per gallon as a guideline.  

        You can, nowadays, buy metal halides mounted in hoods (Coralife-
Energy  Savers),  or  as pendants (Thiel-Aqua-Tech ).  Which one of these 
types to prefer is  a totally personal choice.   

         Both  types are  equally effective  at providing the right light
  for  your corals and invertebrates.  Hoods are closer to the water, and 
may  thus  be  more  efficient  than pendants; pendants on the other hand 
leave  the  top  of  the  tank open,  and appear more attractive to some.  
There  are  many  similar  trivial differences  of that type between both 
and,  as  a  result,  there  are  proponents and opponents of both types.  
Fortunately  both  types are available for sale in both the United States 
and Canada, and so the choice is yours.  

         If  the  light  intensity  you require, or plan to use, is lower
  than  175 watt, no 5500 K bulbs are available at this time.  You can of 
course  still use such  a bulb, but in pendant form.  This will allow you 
to  place  it a distance from the water, thus reducing the intensity, and 
spreading  the  light out better over the entire aquarium.  Alternatively 
you  should  use  4300  K bulbs, which are available in 100 and 175 watts 
versions.  

        Contrary  to popular belief, based on some articles that appeared 
in hobby magazines, metal halide light gives off a lot of "blue" light as 
well, especially the newer 5500 Kelvin degree Coralife bulbs.  

        Cost  is always a factor, unfortunately.  Metal halide lights can 
be  expensive,  especially  if you need several of them.  Buying pendants 
can be a significant expense, albeit a good one.   

        Fortunately,  Energy Savers Coralife came to the rescue some time 
ago  by   offering,  what  they  refer  to  as, The Light Spot, a sort of 
do-it-yourself  metal   halide lighting set-up, greatly reducing the cost 
of  installing  metal  halides  over your aquarium.  For more information 
call  them direct, they advertise in all  hobby magazines.  We tried one, 
and can attest to the fact that their installation is really very simple, 
and the price is right too...  

         Fluorescent Lighting 

         Many  Hobbyists  now use fluorescent tubes over their tanks.  At 
Thiel-Aqua-Tech  we  have used both metal halide lighting and fluorescent 
tubes  too.   We  have,  as  you  may have surmized, found that over reef 
aquariums metal halide lights give much better results, and have switched 
to using only the latter type.  We also described the results earlier.  

        If  you are now using fluorescent tubes, or are considering doing 
so, our  recommendations are as follows : 
         - use daylight tubes (5000 to 5500 kelvin degrees)  
         - use as many as you can place over the tank  
         - use only one actinic if you absolutely feel you must
         - only run the actinic for a few hours a day  
         - follow the guidelines given earlier with regard to intensity
         - change the bulbs about every 7 to 8 months.
         - run your lights for at least 12 hours a day.
         - if the bulbs you are now using are older than 6 months,
         definitely change them, and install new daylight ones.  

         Because  it often is difficult, if not impossible, to get enough 
regular  fluorescent tubes (400mA) over the aquarium to match the minimum 
of  2.5  watt  per   gallon recommended, one solution that many Hobbyists 
resort  to, is to use high  output (800mA) fluorescent tubes.  Such bulbs 
give  more  intensity  per watt, and can be a viable solution, albeit not 
necessarily a less expensive one than using  metal halides.  

         Check  with Energy Savers, as that company offers a wide variety 
of  hoods,  in  many  configurations,  and  may be able to come up with a 
workable  solution  for  you.   You could, for example, get the hood from 
them, and acquire bulbs elsewhere, if that is the way you decide to go.  

         Besides  regular  and  high  output fluorescent tubes, some spe- 
cialty  lights  are  available  as well.  Usually these lights are of the 
daylight  or  higher  spectrum, and are worth considering too.  We do not 
recommend  very  high  output  (1200m  A)  tubes, because they lose their 
spectrum  very  quickly,  and  would need replacing every 3 months or so, 
making their use a very expensive way to go.  

         Because new types of lighting appear on the market all the time, 
watching  for new developments in this area is certainly something a Reef 
Hobbyist  should do.  As techniques evolve, and progress is made, one can 
be  sure  that  leading  lighting  companies  such  as Energy Savers, for 
example,  will  bring  you  what  is  state-of-the-art  as  time goes on.  
Progress  is  what  makes  this  hobby  exciting,  challenging and moving 
forward to bring us even better reef aquariums.  

         At  this  stage  of  affairs in the Reef hobby, the best that is 
available,   in  my  experience,  are  the daylight metal halides made by 
Coralife.   I  highly  recommend  them,  and  use  them myself with great 
success.  Their price is also less than a third of the 4300 K Osram bulbs 
advocated by some German circles.


[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]

5.  Maintenance - Husbandry 
                 
          Regardless  of how well you set your aquarium up, regardless of 
the  expense  you  go  to equipment-wise, if you do not maintain both the 
aquarium, and service the equipment, problems are in store for you.  Even 
the  best  of  equipment needs to be serviced from time to time; the best 
pumps  money  can  buy  need  cleaning from time to time; the best filter 
around needs cleaning out too, etc.  

        Husbandry and maintenance are really two different tasks.  Maint-
enance is  taking care of your tank's equipment.  Husbandry is caring for 
the  tank  itself,   i.e.   the  water  changes,  cleaning the substrate, 
removing  detritus, taking out dead or dying algae, adding water to comp- 
ensate  for  evaporation,  dispensing water  additives, testing the water 
quality  at  regular  intervals, and tasks of that nature.  Both are very 
distinct of each other.  

         Maintenance is necessary mostly to prevent either : 

         - equipment failure 
         - equipment malfunction 
         - erroneous  readings if you use meters to monitor certain water
         conditions 
         - problems with equipment that can directly and quickly
         influence the water quality, which in turn affects the          
         lifeforms.  

         Husbandry  are  all  those tasks that ensure that once the water 
quality  is  good, that it remains there, and that your tank always looks 
at   its   best.   Husbandry  requires  more  work,  and  certainly  more 
dedication.   In  highly  automated  systems  a lot of these tasks can be 
automated  and  do not have to be performed by the  tank's owner.  In our 
small  Reef,  the one discussed in this book, this is not the case.  You, 
the  Hobbyist  will have to perform the work, and you will have to do  so 
on a regular basis, not just once in a while, when you think about it, or 
when it is convenient. 

         Successful  tanks, especially reef tanks, cannot be kept if they 
are  not   cared for as they need to be.  Let's face it, the best of cars 
needs  maintenance   and  care  too;  the  best  of golf clubs need to be 
properly  taken care of; the best  of SCUBA gear needs constant attention 
to  keep it in top shape.  Well, the same  applies to your reef tank, and 
even  more  so,  because  you  are  dealing with live animals and invert- 
brates.  

         The  quality  of the water in which they live is as important to 
them, as  the air you breathe is to you.  Even more so, because they, the 
lifeforms  in  the  tank, cannot do anything about it.  They have to rely 
on you, the owner of the aquarium.  

        If all those reasons are not enough yet to convince you, think of 
all  the  money you have invested in a reef system, and in the  rocks and 
lifeforms that  are in it.  Replacing livestock that died because you did 
not  take  proper  care  of   the  tank,  can  be  very expensive, but is 
something  you  can control, something you can avoid.  All you have to do 
is  "care"  for  the  hobby  you  got  into.   Tanks  do not take care of 
themselves...  

         I  have  outlined,  in  great  detail,  a schedule for reef tank 
maintenance  in  my  book : The Marine Fish and Invert Reef Aquarium, one 
geared  to more automated systems.  Disregard the items that do not apply 
to  you, and take care of the  others.  If you do not have the book it is 
available from stores nationwide, or from us directly.  

         What  I  am  more  concerned  with  here, in Small Reef Aquarium 
Basics,  is  husbandry,  not because maintenance is not important, it is, 
but  because  little  is   written about husbandry in magazines and other 
books  that  deal  with  Reef  tanks  (  of course there aren't that many 
available to begin with).  

         Let's  review  some  of the tasks that I consider important, and 
that  I  perform  myself on my home aquarium, and on the tanks we keep at 
the business : 

         Cleaning  :  Cleaning includes several areas of concern.  A very  
important  one  is  the tank bottom : you should remove any dead material
uneaten   food,  organic  detritus, dead algae, etc.  as soon as you  see  
it.   Do not let it decompose, all such achieves is fouling the water  up  
by producing breakdown products that increase the  load on the biological  
filters,  by  producing  ammonia, and subsequently nitrite,  and nitrate,  
not to speak of other by-products, phosphates, both organic and inorganic 
being just two of them.  

         Of  course, dead fish, or dead invertebrates, however small they 
may  be,  should be taken out at once.  All that you would achieve by not 
doing  so, is letting them "rot" so to speak, and stress your filters, as 
well  as  all the lifeforms in the tank.  Organic breakdown not only adds 
noxious  compounds  "to"  the  water,  but it takes beneficial compounds, 
e.g.  oxygen "out" of the water.  That is a double-edged sword.  

        Often, a greyish to brownish material referred to in the hobby as 
mulm,  collects on the bottom of the tank.  Incidentally, I have not been 
able  to  find  an  exact definition for that word in 5 different compre-
hensive  dictionaries  I  looked  into,  including the latest 2nd Edition  
of   The  Random  House  Unabridged  Dictionary  of the English Language,  
and   Science   and   Technology   dictionaries as well.  Mulm is usually 
defined,  in  the hobby, as material that is totally mineralized, meaning  
it cannot break down further, and is, therefore, considered harmless.
   

         The  problem is how does the hobbyist know whether it is mulm or 
not  that   is  lying  on  the  bottom  of the tank ?  My recommendation, 
therefore,  is  that you  syphon off anything that lies on the substrate, 
or  bottom,  or  rocks,  that is not  something you yourself added to the 
aquarium.  You might call it the better safe than sorry approach.  

        Most important for you is to clean all your mechanical filters at 
least   once  a week, and preferably more often.  Any material trapped in 
the  filters  is  still part of the system, as I explained elsewhere, the 
only  difference  is, that  you do not see it anymore.  Leaving it in the 
filters,  will start decay with the  resulting reduction in oxygen in the 
water, the  appearance of ammonia, etc.  You  may not look at it as such, 
but  an  overflow corner filter, a syphon surface skimmer, and other such 
items, also trap dirt and need to be cleaned.  

         The  bottom  of  the  trickle  filter,  the  drip plate, and any 
mechanical filtering device you may have inside the trickle filter, falls 
in this category as well. The same applies, of course, to micron filters,
sand filters, and other such canister type arrangements.  

          

         Some  Hobbyists like to clean the rocks in the tank from time to 
time,  to   remove  accumulated dust and other material.  That is usually 
best   done  by  directing the output of a very small power head at them, 
and  letting the dust and other  material get caught in your normal mech-
anical  filters. If  you  are  going  to do  this, do it before you clean
your   mechanical   filters.    It will save you from cleaning them twice 
the  same  day,  or  within a day of each other.  While on the subject of  
powerheads, they  have a tendency to collect dirt too, and must be clean-
ed as well.  

         It  is obvious, but for the sake of being complete, the glass or 
acrylic of the tank must be cleaned regularly as well, including the back
and  sides.   They may be harder to get to, but clean as much as you can.   
Whatever  you  can  remove,  is  no  longer part of the system and cannot 
decay, as a result.  

        Water Changes and Level Adjustments : 

        I have made recommendationson how to do this, how often, and why, 
elsewhere in this book  already. Istress again though, that I really feel 
that  changing  water is an absolute must. Don't be fooled by advertising
that claims that  if   youuse  such and such a product you no longer need 
to  change  water. In my  experience such is not possible.  You must make
regular  and  small  water  changes.   Your   tank will look much better, 
and more vibrant.  

         Although  not  necessarily  a form of cleaning, chemical filters 
such  as  Poly Filters, activated carbon, resins, etc.  need to be either 
changed  on  a  regular basis, or in the case of Poly Filters, rinsed and 
evaluated  to  determine  whether or not they can be used for longer.  If 
you  are  a  firm  believer  in activated  carbon, and rely on it as your 
chemical  filter,  change  it every few weeks; depending on the load your 
tank  carries,  sooner or later.  I usually recommend a maximum of 4 to 5 
weeks.  

         Water  Quality Management :         

The  only way for you to know how good, or bad,  the water quality really
is,  is  by  testing  it  on a regular  basis,  and  keeping notes of the 
results  in  a  diary.  Testing, and  keeping  records,  is  an  absolute  
must in a basic reef aquarium, because you cannot rely on instrumentation 
to monitor conditions for you.  

         Additionally,  by keeping records you will be able to build up a 
history  of how your tank "behaves", so to speak.  Any deviation in water 
quality  parameters will then become more obvious, as you will be able to 
refer to  previous readings of a particular item, compound, or state that 
you are testing for.  

         We  suggest  that  you  acquire  the following tests :         
-  ammonia
-  nitrite
-  nitrate  (low  range)
-  phosphate  (low  range)
-  dissolved  oxygen (in mg/l)
-  residual  ozone  (if  you  are  using  an  ozonizer)
-  carbonate hardness
-  iron (if you keep macro-algae and fertilize)
-  pH
-  and a real accurate thermometer.  

         There  are  many  other  tests still, such as silicate, and high 
range  nitrate and phosphate, copper, carbon dioxide, amongst others, but 
I personally feel  you do not need those in a basic reef tank.  

        Perform  tests on a regular schedule, and keep notes.  Some tests 
you may want to perform more often than others.  Dissolved oxygen, pH and
carbonate  hardness  are  but  three.   Other  tests you may only want to 
perform  once a week.  The key is however to "make" the tests and, again, 
keep records  so you have something  to look back at to detemine how your 
tank  is  doing  this  time,  versus  the  last  time  you tested.  It is 
unreasonable  to expect  that you will remember what the dissolved oxygen 
levels, for instance, were the last time you tested.  

        Of  course, testing has one other major advantage : you learn all 
there  is  to  know  about your tank.  You would be surprised how helpful 
that will be, when someday something goes awry.  

        When your tank does not look good, and you need to determine what  
to  do,  to  bring  it back to its usual shape, you will need not only to 
have  the  tests  available,  but know how to interpret the results.  You 
will  also  need  to know where the tank is different, test-wise, when it 
looks  out of shape.  If you have no  notes to refer to, such will not be 
possible, or to  say the least, extremely hard to do.  That, then, brings 
about  more problems because you will not know how to  react, because you 
basically  do   not  know what to react to.  Such puts you in a situation 
where  the  tank controls "you" and not vice-versa.  You should never let  
that happen.  You should be the one in control.   

         Time  and time again I get phone calls that make it evident that 
the  Hobbyist  has  no  clue  what  any  of  the values that are normally
measured  are,  or  were  ,  when  the  tank  looked good.  That makes it 
practically impossible for me to help  them.  Indeed, what do I go by, to 
recommend  a  cure ?  Stating, for instance, my  fish have "ich", is only 
the  result  of  some  tank  water chemistry  disorder.  The problem lies 
elsewhere.    The   fish   became   infected  with ich, because they were 
stressed.  The key is, then, to determine where the stress came from, and 
to do that, one  needs  water quality parameters  to make a diagnosis and
suggestions.   

         There  is  one test that needs to be performed that has not been 
mentioned   yet  : salinity, or specific gravity.  There are several ways 
to  do  so.   A good hydrometer, or a salinometer,  or a special salinity 
test  (for  example  the one sold  by Lamotte Chemicals).  Most hobbyists 
use  a  hydrometer, and that is perfectly  fine, as  long as it is a unit 
that  has  been calibrated for aquarium use,  temperature-wise.  Many are 
calibrated  for  59 degrees Fahrenheit and not  75-76, the temperature at 
which you normally run your tank, or should  anyway.  In this respect you 
may  wish  to  refer  to  Martin  Moe's  first book : The Marine Aquarium 
Handbook,    beginner   to  breeder,  for  a  chart  that  indicates  the 
adjustments to be made at various temperatures.  

         Where  do  you  get all these tests ?  Companies such as Route 4 
Marine  Technology,  my  own  company, and some others, offer an array of 
tests.   The  key  is  to   get  the  right  ones.  When, for instance, I 
indicated that you should get the "low  range", I suggest you do.  A high 
range  test  is  of little value in a reef tank.   You can also get tests 
from  the companies that make them, e.g.  LaMotte, Chemetrics, Ecological 
Labs,  Hach, etc.  but they usually only sell lots, not single tests, and 
may  get more money for their tests than if you went through say, Route 4  
Marine Tech, or one of their many distributors.  

         For  each  of  the  measurements  (tests)  suggested, there are, 
obviously  ideal,  acceptable,  and  non acceptable levels.  Many authors 
differ  in  opinion  on what those various numbers should be.  I can give 
you  the  ones  that I usually recommend, and have found to be safe.  You 
may wish to check some other sources, if you  want a second opinion.  

        I have found, over time, that for many parameters it is difficult 
to  differentiate  between  ideal and acceptable, so I will only list one 
number,  or  a  range  in parts per million, or milligrams per liter :         

-  Ammonia              0.00 ppm         
- Nitrite               0.00 to 0.1 ppm maximum          
- Nitrate               1.00 ppm N-NO3 maximum        
- Nitrate               5.00 ppm as NO3         
- Dissolved 02          saturation or  higher,  usually  >7mg/l         
- Phosphate             0.1 to 0.2 ppm total PO4           
- Copper                0.00  ppm (except for traces in the salt)         
- Iron                  0.1  to  0.5  ppm  maximum         
- Residual 03           none detectable  with  O-tolidine  tests          
- Carbonate             Hardness of 5.35-6.45 meq/lor as some express it
                        15 to 18 dKH  (German  degrees)          
- Calcium               Hardness  of  60-80 ppm         
- pH                    8.0  to  8.3          
- Spec.Grav.            1.022to1.025, preferably the latter          
-  Temperature          75  to  76  Fahrenheit         
-  Redox pot.           350-390 mv in the tank itself                         
                        A recent article in Marine Reef gives a much more
                        detailed  review (Vol 2 Nr 22)         
- Conductivity          Around 51000 to 53000 microsiemens         
- TDS                   total dissolved solids 460-470 ppm 

         Keep  in  mind  that  in  your  small  reef  tank you may not be 
measuring  several  of these, since you will not be using instruments, or 
at least not automation  instrumentation such as "controllers".  They are 
just  given as a reference, because some Hobbyists use so-called pen-type 
meters.  

         With  the  risk  of being accused of repeating myself, test on a 
regular  basis,  and keep notes.  Add a comment or two about the animals, 
respectively invertebrates in the tank, how they looked, and very import-
antly: the time of day,  and how long after feeding time that you perorm-
ed  these  tests.  Adding  food  will  affect many tests; you should,as a 
result,  not  test within 4 hours of feeding.   Best is to always test at  
the   same   time  of  day,  or if you test more than once, to also match 
those  times, as many tests are affected by the rate of metabolism of the 
animals.            

        Additives:
       Water quality management includes the  addition  of  a  number  of  
water  additives, i.e.  trace elements, vitamins, KSM, Iodine, and others 
discussed  elsewhere in the book.  This is  an  important  part  of  good  
tank   husbandry.   You should set  up a regular schedule for yourself to 
do  so,  based  on the conclusions you have drawn  for  your  tank,  from  
the   material  you  have  read  about  these additives in this and other 
books.  

        Visual  Inspection :
         Often  you  just  "look"  at  your  tank.   From  time  to time, 
however,  you  should  consider  this a detailed visual inspection.   Not  
only   will  you learn a lot about your aquarium, i.e.  what small animal 
life  is  in  it,  but  it  may  pinpoint actions you have to take.   For  
example,  you  may notice dead algae underneath some rocks, something you 
would not see if you just looked briefly at the aquarium.  

         Inspect  your  aquarium  at  night too, not just during the day.  
Again,  you   will notice animal life that you normally do not see during 
the  day; you will learn how some of the animals, and invertebrates, that 
you keep look after the lights are out, and you may, again, find that you
need  to take some action, i.e.  you may see bristle worms which you will 
have to try to remove somehow.  

         Taking  Corrective Action :
         
          Of  course,  anytime something is wrong with the tank, you will 
have  to  take  corrective  action  to  bring the tank back to its normal 
shape.   The  latter really means bringing the water  chemistry  back  to 
where  it  should be, at least in 99  percent of the  cases.   What to do 
in  each  situation is not part of this book, but there  are  many  other  
ones,  and  of  course  Marine Reef, our Newsletter, that give advice for 
many types of actions that you may need and want to undertake.  

         You  could  also  call or talk to your local Pet Shop, the local 
Aquarium  Society,  or call someone whose opinion you respect, especially 
after you have exhausted all other avenues.  Many volumes could be writt-
en   about  what  to do when something go wrong in a reef tank, and still 
each   situation   would  be unique, because each tank is different.  The  
filtration  differs, the animal population is not  the same, one tank has 
macro-algae,  another  one  not,  some  tanks have lots of invertebrates, 
others  do  not,  one  is  well  taken  care  of,  another  one not, etc.          

        Feeding :
         
        Feeding  is also part of good husbandry.  Feeding a Reef Aquarium  
is   however quite more complex than feeding a fish-only tank, because of 
the difference  in the nature of the animals kept.  

        There  are so many different manufacturers of fish foods nowadays 
that  it  is  easy  to get confused.  One thing is clear however : I said 
"fish"  food  not  reef tank food.  In the reef tank food area the choice 
boils  down  to very few.  Those who have taken the time to develop foods 
specifically  designed  for  corals  and   invertebrates  that need extra 
nutrition, besides what they can gather from the  photosynthesis of their 
symbiotic algae, the Zooxanthellae.  One such company is  Coralife, which 
offers  not  only excellent liquid food varieties, but also frozen  ones.  
I  can  highly  recommend their foods, and use them myself in addition to 
the ones made by my own company (Reef Smack Melange).  

        Feeding  is  a  process that is complex, insomuch as each type of 
animal  you keep may  have  different  requirements.  This  makes it nec-
essary  to  feed  highly   complex and complete forms of food.  This also 
makes  it  hard for me to recommend  what, and how often, you should feed 
the  lifeforms  that you may be keeping in your tank, in this short book.  
It is, however, one of the main topics of my book:  Advanced Reef Keeping 
II, also  published by Aardvark Press.  The best advice I can give you is 
to  buy a food developed for the reef aquarium, not some fancy food  in a 
fancy   container,  that  is  really  meant  for  fish,  and  follow  the 
manufacturers  instructions,  keeping  in  mind  that  they  are  usually 
conservative.   On  the  other  hand,  do  not  over-feed either, as that 
increases  the amount of organic load that your filters will have to deal 
with, and may, as a result, affect your water  quality.  

        Adding  Lifeforms :
         
        Although,  technically  speaking,  not  part  of husbandry, it is 
important  to  be  very careful when adding new lifeforms  to  your tank, 
especially  fish.   Make   sure  that  the  stock  you  get  is  "clean",  
meaning  free of parasites.  How is this done ?  By placing the fish in a 
so-called  hospital  tank  for  a  few  days  and observing  it.   Or  by  
treating  the fish with medication and using the drip method.   Add   the  
fish   to  your  tank  only  after you have dripped water from  the  tank  
into  a  bucket,  where you have placed the fish, and some medicine,  for  
about  45 minutes.  Much more on this subject is found in Marine Reef and 
Advanced Reef Keeping II.    

 

 

6.  Miscellaneous mixed short Topics 

        Small  Reef  Aquarium Basics is by no means an encyclopedic work.  
I  tried   to  cover as much of what I felt was necessary for the average 
Hobbyist  to  know,   to  set  up  a  successful  reef  aquarium, without 
incurring huge expenditures.  You may want to read up on some of the more
basic  topics in other books.  I have recommended a few, and particularly
like   Martin  Moe's : The Marine Aquarium Reference .  There are  a  few 
topics, however, that I briefly want to address in these last  pages : 

        Heating and Cooling:
          
       You  must try to keep the temperature  of the reef tank stable The 
one I recommend is between 75and 77  F!.   Whether that requires heaters, 
in  your  case,   is something only  you can decide.  If the tank is in a 
cool,  perhaps air-conditioned room,  probably  yes.  Many Hobbyists find 
that  their  tanks  run  too  warm.   Adding  a  cooler is of course very 
expensive.   You  may have to try and determine why the tank runs so hot.  
Perhaps the pumps ?  Or the lights, especially  if  no  fan  extracts the 
heat  from  the  canopy.  Usually the problem  can be isolated and solved 
without having to resort to buying a chiller.  

        Cycling the Tank :
          
        Refer  to the many articles that appeared  in  magazines  such as 
FAMA  and Marine Reef, and other books.  Doing  it  the  right  way  is a 
very important part of  ending up with a successful  tank, and you should 
read  up  on  this process before  starting your  aquarium.  The more you 
know, the better off you, and your tank will be.  

        Instrumentation:
          
        Although I do not advocate fancy controllers  and instruments for
the  basic reef tank, there are some of you who will want to acquire some 
form   of  electronic  control  method  over  pH,   and   perhaps   redox  
potential.   That  is  of  course  fine  .  Buy instrumentation  that was 
developed  for the reef tank, not something that i s offered for sale but 
was  originally  made for industry, where "rough" rather  than  "precise" 
measurements  are  the norm.  Lab equipment is of course  great,  but  so   
will   the   price   be.    And   if you do buy such equipment,  the  one  
thing   to  look  for  is the degree of accuracy it offers,  e.g.  in the 
case  of  a  redox  unit,  how  many millivolt, or what percentage of the 
scale.   For  example, a 1- of scale error on a meter that can  show from 
-1999  to  +1999 is 40 mv.  Take heed.  On a meter running from  -999  to  
+999   the  error  is  still  20  mv.   Be  aware that the reason certain  
instruments  cost  more   is very simple: they are accurate, or should  I  
say  much more accurate.  I know  of only three companies that make  such  
instruments    specifically   for   the   hobby  :   Sanders,  Tunze  and 
Thiel-Aqua-Tech, which has them manufactured in the USA.  

        Pen-type  meters are all right, but be aware that they may not be 
all  that  accurate.  If  you can live with that, then buy as an educated 
consumer,  knowing  that the reading you get may be somewhat off.  If you 
decide  to  get  some  form  of  instrument,  the one I recommend you get 
first,  is  a  redox potential meter, and  buy a real good electrode, not 
general  purpose  types,  so often advertised in magazines.  You may even 
want  to  buy  the  electrode  from someone else, e.g.  a company such as 
Cole  Parmer  in  Chicago,  who  offer a very wide variety of electrodes,  
controllers  and  meters.  I  personally use the Hach, refillable, liquid 
double junction electrodes, and  have been extremely satisfied with them,
but  they are expensive, much more, for instance, than a Bradley James.  

         Instruments,  especially controller type instruments, make one's 
life  easier,  and  tank  conditions  very stable, but greatly add to the 
cost  of the tank.  And that is not what we had in mind when writing this 
book.  If  you  want to know how to install such automated aquariums, you 
may want to read my other books.  

        Equipment such as Reactors :
        
        Several companies offer pressure  operated  reactors  for various 
purposes,  e.g. oxygen, ozone, carbon dioxide, carbonate hardness, and so 
on.   Although  they  definitely  assist   in  maintaining  a more stable 
environment,  I do not consider  them to  be  part  of  the  small  reef, 
rather,  they  are  positioned  somewhere  between   the  basic  and  the 
automated reef.  

        If  they  are  of  interest  to  you,  check into the products of 
companies  such as Marine Technical Concepts, Route 4 Marine Tech, my own
company,   and   several  others  that  advertise  in the magazines.  But 
before  you  buy,  read up on exactly  what these units do, or can do for 
you. 
          
        Of particular interest to many Hobbyists who set up reef tanks is 
the   so  -called  oxygen  reactor,  described at length in both my other  
books.    Air   is   forced into a cylinder, usually tall, and mixed with  
water  coming  from  the sump of the trickle filter, or main water return  
line   to  the  aquarium.   Because  air contains oxygen (about 21 -) and 
because  the  process  operates under over pressure -anywhere from 1 to 5  
psi  is  not  uncommon-  this oxygen is forced into the water, and  super 
oxygenates  the  aquarium's  water.   This  type of reactor is beneficial 
only,   if  all  other  methods  that you already use (filters, skimmers, 
ozone),  do  not  result  in oxygen saturation.  If you already have high 
levels  of dissolved oxygen there is no need, and no benefit, to install-
such a reactor.  

        The ozone reactor operates on the same principle.  Instead of air 
alone,   a  mixture of air and ozone are injected into the reactor.  This 
forces  the  ozone   into  the  water, which results in dissolved and non 
dissolved organic material being quickly oxidized, since ozone has a very
higg  oxidative  power. This, in turn, results  in the redox potential of 
the   water   in   the  tank being raised, meaning  the tank's water  has  
become   purer,   and  the  living environment for the tank's inhabitants  
better.    Ozone   reactors   are  trickier  to adjust than oxygen types,  
but   with   a few trial and error settings most Hobbyists do not seem to 
have  any  problem  s with them.  Noteworthy about these reactors is that  
they   greatly   improve  the  water  quality,  but  that it is better to 
operate   them if you have some way of measuring the redox potential, and 
you  must have a residual ozone test.  Because they  are so efficient, it 
is  most important that you ensure that the water flowing out of an ozone 
reactor  passes  through  activated  carbon  first,  as  this will remove 
residual ozone.  

        In a system that is not overloaded, ozone is usually not required 
to  maintain  a  high  water quality.  It is my experience, however, that 
most Hobbyists overload their systems, and tax the filtration too much as
a  result,  requiring  them to install an ozonizer on the system as well. 
For a much more detailed look at ozone, refer to my two other books.  

         Many  other devices are used on reef tanks, e.g.  carbon dioxide 
injection, carbonate hardness reactors, tangential flow filters, special-
ized  resins,  highly  sophisticated dosing pumps, oxygen/peroxide/marble  
generators,   and  so on.  I do not consider them part of the Small Reef, 
and have, as a result, not covered them.            

        Conclusion : 

        No book can claim to be complete.  Reef Systems are so intricate, 
that   special  situations always exist.  I have attempted to give you my 
personal  way  of   setting up a small reef, on a budget that is livable, 
but will still give a tank  that you can be proud of.  

         Once  you  have a basic set-up, you can always build on what you 
already  have,  and  add  other  devices  that help in maintaining and/or 
improving the water quality.  You can view  this suggestion as a building 
block  approach,  and it is.  If , however, you follow generally accepted 
recommendations  on tank  load, and do not tax your system by adding more 
and  more  animals,  without  regard  for the filtration, you will, in my 
opinion,  not  need to add any other devices.  All you may want to do, is 
to  add some form of instrumentation that will make testing, and monitor- 
ing, a less time consuming task.
                   
         I  hope  you  have  enjoyed   this   third  book  of  mine,  and  
welcome   any  suggestions  for  additions  in future editions.  Advanced 
Reef  Keeping  Made  Simple,  and  The   Marine   Fish  and  Invert  Reef  
Aquarium,   take  a close look at more automated  systems,  and  although  
you   may   not  want to set up such a system,  you may want to read  the 
books  anyway,  just  to  learn more about tank   technology.   I  highly  
recommend    that   you  subscribe  to  our newsletter  Marine  Reef,  as  
it  will  keep  you  up  to  date  on the latest developments in the Reef 
Hobby.  

         Advanced  Reef Keeping II, the book dealing with the animal life 
in  the  aquarium, may or may not be available when you read this, depen-
ding on when you bought this one.  Check with your dealer, or with us.  

          Good   luck   in  your endeavors.  Call Thiel-Aqua-Tech anytime 
you  have   questions   that   you  cannot  get resolved.  We will try to 
help  you,  even  if you are not using our equipment.  And, please, share 
your knowledge with other Hobbyists.


[Albert J. Thiel requests that you make a $5.00 donation to the
New Mexico School for the Visually Handicapped Children, 1900 North 
White Sands, Alamagordo, New Mexico 88310 (or other charitable
group) if you download the entire book. This would be in lieu of
the standard purchase price for this publication.]
Table of Contents 

Introduction                                                      SRAB-1  
Filtration                                                          "
           General Remarks                                          "
Mechanical Filtration                                               "
           Canisters - traditional                                  "
           Canisters - special                                      "
           Diatomaceous Earth filters                               "
           Sand and Gravel Filters                                  "
           Micron and Sub-micron filters                            "
           Miscellaneous                                            "
           Mechanical filter in syphon                              "
           Conclusion on mechanical filtration                      "
Biological Filtration                                             SRAB-2
           General Remarks                                          "
           General principles of trickle filtration                 "
           Components of a good trickle filter                      "
           Sizing the trickle filter                                "
           Media considerations                                     "
           Drip plate or spray bar                                  "
           Making your own drip plate                               "
           Retrofitting for a slanted bottom                        "
           Adding Compartments to the sump                          " 
           Making your own add-on compartments                      " 
           Fittings on the trickle filter                           " 
           Float Switches                                           " 
           Hard pipe or flexible hose                               " 
           Fittings other than on the trickle filter              SRAB-3
           Adding Canister filters                                  " 
           Flow rates through filters and through the tank          " 
           Water returns, with or without holes in bottom           " 
           Corner Overflow, or syphon surface skimmers              " 
           Drip systems as part of the trickle filter               " 
Improving the efficiency of your existing trickle filter            " 
           In-line cartridge filters                                " 
           Automatic float switches                                 " 
Converting from an undergravel to a reef system                     " 
           Maintaining the undergravel                              " 
           Removing the undergravel                                 " 
           Remarks on the conversion process                        " 
Chemical Filtration                                                 "     
           General Remarks                                        SRAB-4  
           Activated carbon                                         " 
           De-ionizing resins                                       " 
           General remarks on resins                                " 
           Molecular absorption filters                             " 
           Additional remarks on the use of activated carbon        " 
Review of Filtration requirements discussed                       SRAB-5
Protein Skimmers - Foam fractionators                               "  
           Checklist for sizing a protein skimmer                   "  
           Skimmer efficiency                                       "  
           Air - water contact time                                 "  
           Size of air bubbles                                      "  
           Shape of the skimmer                                     "  
           Salinity of the water                                    "  
           Water level in the skimmer                               "  
           Water additives used                                     "  
           Optimum water flow                                       "  
           Venturi Power skimmers                                   "  
Conversion Units - Hang-on Units                                    "
Water Sources, Uses and Treatment                                 SRAB-6
           Introduction                                             "  
           Water Sources                                            "  
           Water uses                                               "  
           Water changes                                            "  
           How to change water (manual and automatic)               "  
           Treating the water before it is used                     "  
           Mechanically 121 Sand and similar filters                "  
           Activated carbon as a pre-filter                         "  
           Molecular absorption as a pre-filter                     "  
           Reverse osmosis as a pre-filtration method               "  
           De-ionization as a pre-filtration method                 "  
           Ultra-violet sterilization                               "  
           Ozonization 132 Chemical Additives                       "  
           Cold sterilization                                       "  
           Suggested pre-filtration set-up with diagram             "  
Water Additives and Salt                                          SRAB-7
           Reef aquarium salt                                       "  
           Trace Elements                                           "  
           Vitamins                                                 "  
           Special Additives                                        "  
           Conclusion on additives                                  "  
Lighting for the Reef Tank                                          "  
           Introduction                                             "  
           Metal Halide lights and corals                           "  
           Fluorescent lighting                                     "  
           Changing lighting                                        "  
Maintenance and Husbandry                                         SRAB-8
           Cleaning                                                 "  
           Water changes and Level Adjustments                      "  
           Water Quality management                                 "  
           Tests                                                    "  
           Recommended water quality parameters                     "  
           Additives                                                "  
           Visual Inspection                                        "  
           Taking corrective action                                 "  
           Feeding                                                  "  
           Adding more Lifeforms                                    "  
Miscellaneous short Topics                                          "  
           Heating and cooling                                      "  
           Cycling the tank                                         "  
           Intrumentation                                           "  
           Equipment such as Reactors                               "  
Conclusion                                                          "  

(c) 1989,1990 Albert J.  Thiel 

2 nd Printing.  January 1990