Description

This article is from the Beginning Saltwater FAQ, by Thomas Sasala with numerous contributions by others.

03 The Basic Components

Now that we are comfortable with the basic parameters of a saltwater
aquarium, let's look into what is needed to run a successful tank.

The components needed to run a successful saltwater tank depends a lot
on who you talk to. You should never operate solely under the advice
of one person. For example, many people advocate using under gravel
filters for biological filtration. This however, must be tempered with
wisdom. A saltwater tank running an under gravel filter (UGF) with
minimal circulation will be much more work than a than a system
running a wet/dry filter and a couple of powerheads. Wet/Dry filters
tend to require less maintenance, as UGF's tend to become clogged over
time.

Not to get too buried in details, the basic components of a saltwater
tank are the tank, decorations, filtration (including protein
skimming), lighting, water, and test kits.

One of the most important decisions in starting a saltwater aquarium
will be the size of the tank. The basic rule of thumb is the bigger
the better. A larger tank will be easier to control and gives a bit
more leeway for mistakes (which are inevitable). The smallest tank for
beginners should be no less than 20 gallons, with 55 gallons being
even better. For someone versed in fish keeping (i.e., converting from
fresh to saltwater), a 10 or 15 gallon tank will work, but is not
suggested. In general, fish like long, wide tanks. The more surface
area a tank has, the better the gas exchange will be and the happier
the fish will be.

Before finalizing on a tank size, remember that fish densities are
much lower for saltwater than freshwater. That is, you can not put as
many fish in a saltwater tank as you can in a freshwater tank. Putting
more than 2 saltwater fish in 10 gallon tank is asking for trouble. A
general rule of thumb is 4" (10cm) of small-to-medium fish per 10
gallons, or 2" (5cm) of larger/fast growing fish per 10 gallons. This
is just a rough estimate of the number of fish. There is no exact
number since finding the stocking density has to take into account the
filtration, maintenance, feeding schedule, etc..

Beyond the number of fish you wish to keep, the tank's size will also
affect your filtration and lighting choices, both in cost and design.
Tanks which are 48 inches (122cm) long are usually cheaper to light
because the lamps are more readily available. However, the larger the
tank, the more light you will need to provide your inhabitants.
Moreover, a larger tank needs efficient filtration to keep the system
thriving. A good size tank is around 55 gallons.

As a note, scrutinize hoods carefully. Many of them are designed for
48" tanks, but require two 24" lamps rather than one 48" lamp. (24"
lamps are usually more expensive than 48" lamps.)

Once you have decided on a tank, make sure you have a place to put it.
The tank should not be in direct sunlight or in an area which is very
drafty. Also, make very certain the stand will be capable of holding
the weight of the tank, plus substrate, plus rocks, plus water. In
total, a 55 gallon tank will probably weigh over 800 pounds.

After selecting the tank, consideration must be given to the
substrate. It is best to use a calcareous substrate such as crushed
coral or dolomite. These substrates will, at least initially, help
buffer the water by adding ions to the buffering system. Generally the
substrate should not be so tiny as to get sucked into the filter or
pumps, and not so large as to make the tank unsightly. Also, some fish
(e.g., Gobies) like smaller grades of substrate over larger ones.
Something in the 2-5mm department seems average.

Live sand is one substrate which has recently gained a fair amount of
publicity. This technology is really in its infancy and is not
recommended for beginners. You can find more information in the
ARCHIVE.

After you select a substrate, consider the filtration system you plan
to use. Your choice in filtration may impact the amount to substrate
you need. A UGF or RUGF filter should have about 2-3" (5cm) of medium
grade (2-3mm) substrate covering the filter plate. You do not need
substrate when you use non-UGF filters (e.g., hang-on-the-back power
filters), but, most people use between a 1/2" to 1" for such tanks.
It's interesting to note that too much substrate in a non-UGF system
might lead to dead spots, which can kill your inhabitants (a plug for
regular gravel cleaning). More detailed information about filtration
can be found in the FILTER FAQ.

Next, consider the decorations, of which there are a cornucopia of
choices. Dead coral, lava rock, tufa rock, live rock, and many more.
Coral pieces are the most popular, but are also some of the most
expensive. Lava and tufa rock are inexpensive and may also be stacked
to make interesting reef looking tanks. Live rock is one of those buzz
words that people like to throw around and one which gets a lot of
hype. Live rock is simply rock taken from a reef system which has been
populated by many different organisms.

Many aquarist dedicated to fish-only setups are beginning to discover
the benefits of having live rock in their system. Live rock produces a
more natural environment for the fish and also aids in nitrification
and denitrification. This implies that the live rock is more that just
a decoration, it is actually part of the filtration system. Although
it is difficult to use live rock as the sole source of filtration in a
fish-only setup, it certainly can be used effectively to reduce
nitrates. The use of live rock in fish-only setups must be closely
monitored though. If nutrient levels in the aquarium are high, the
live rock will be the first to demonstrate this fact. Live rock in
presence of high nutrient levels will grow unhealthy amounts of hair
algae, and in some cases, cyanobacteria (slime algae). To avoid
outbreaks of plague algaes, a few simple rules must be followed.

First, you must start will high quality live rock; live rock which is
highly encrusted in coralline algae. Avoid live rock which already has
hair algae growing on it. Regular additions of calcium may also be
needed to keep the coralline algae thriving. Next, you need to keep
nitrate levels low (~10ppm) and ensure you have nearly undetectable
levels of phosphate (~0.02 ppm). Finally, feed sparingly; decomposing
food is one of the main avenues for introducing phosphate/nitrate and
contributing to alga e problems.

If you plan to add live rock to your system, remember live rock
contains living organisms, so they can be killed along with any other
organism in your tank. It's a good idea to wait until after the tank
is set up before buying live rock. There is no good place to store
live rock other than in a circulating tank. Trying to do otherwise
will be disastrous and costly. Also, if you are going to put live rock
into an established tank, the rock must be cured live rock (for a more
detailed discussion of cured live rock, see the REEFKEEPERS' FAQ.

Filtration is covered in detail in its own FAQ, with most of the
information being relatively generic and applicable to marine tanks.
However, there are certain caveats that should be noted. If you decide
to use a UGF, reverse flow setups are better. A RUGF will keep
nitrates lower by keeping the substrate cleaner and will aid water
movement and circulation.

In addition to good filtration, water movement is a must in saltwater
aquaria. Without circulation the system will be unstable and usually
tends to grow unhealthy amounts of algae and other undesirables. The
easiest way to achieve water movement is to have a powerhead in the
tank for circulation. One must be careful though, a medium sized
powerhead in a small tank will easily make a tornado- like environment
and cause problems for small or slow moving creatures.

One of the best possible filtration systems for a fish-only marine
tank is a wet/dry filter. Although commercial setups are fairly
expensive, a wet/dry filter can be made very inexpensively at home
with little effort. The ARCHIVE has a lot of information about
constructing your own W/D filter system (as well as other fish related
projects).

Many people advocate wet/dry filters for marine tanks stating they are
the only acceptable solution. This is simply not true. Any one of the
popular filtration systems may be used for a marine tank. The key to
success is providing adequate biological filtration without trapping
excess detritus. Trapping detritus produces nitrates and inevitably
leads to problem algae outbreaks. Which ever filtration system you
choose, be sure to rinse the mechanical filtration media at least once
a week. Ideally you should rinse the media in old saltwater from the
tank to minimize the disruption of any nitrifying bacteria growing on
the media.

A part of filtration which most recently has gained wide spread
acceptance is protein skimming, or foam fractionation. Protein
skimmers are a must for a decently stocked saltwater tank as they
strip dissolved organic particles from the water before they can be
converted to nitrates.

There are simply too many models and manufacturers to discuss all of
them, but the two basic designs are air-driven and venturi. Air-driven
protein skimmers use a wooden or glass airstone to produce bubbles in
a column of water. Venturi skimmers use a venturi valve to inject
bubbles into the water column. Both air-driven and venturi have
co-current and counter-current designs, with counter-current protein
skimmers being far superior to co-current models.

In deciding on a protein skimmer, there are some basic things to
consider. Air-driven skimmers use airstones which must be replaced on
a regular basis (usually every month or so). Additionally, they
usually require more maintenance than venturi skimmers to maintain
proper skimming. Venturi skimmers on the other hand require very
powerful pumps to achieve effective protein skimming. They are usually
more expensive than air-driven skimmers as well. Also, any skimmer
smaller than 24" should be avoided for heavily loaded tanks.

Whichever type of skimmer you buy, the final cost of the skimmer must
not overlook the need for an external water pump and potentially an
air pump. A $200 venturi protein skimmer usually doesn't include a
$150 high pressure pump; a fact that most people seem to miss the
first time around.

With the setup nearly complete, you need to consider your near-term
and far-term lighting requirements. If you plan on having a fish-only
tank forever, then you only need a single full spectrum bulb. However,
if you plan to advance in your hobby and keep more sensitive animals
such as anemones, you must carefully select your lighting (and
filtration as well). Anemones require very strong, full spectrum
lighting, supplemented with actinic blue. The general rule of thumb is
a minimum of 3-4 watts per gallon, with the higher values for deeper
tanks (greater than 18-24 inches). The standard Perfecto hood will not
provide enough light to keep anemones alive (or other light-loving
invertebrates for that matter).

For a beginning aquarist, fluorescent lighting is probably the best.
Metal halide lighting is really for reef keeping and heavily planted
freshwater tanks. In any case, if you want or will need something more
than a single lamp, your choices are limited. The best thing to do is
to build your own hood with custom lighting, or buy one through mail
order. Fish store prices usually preclude aquarists from getting
proper lighting.

If you select a custom fluorescent hood, then you will have to choose
between normal output (NO), high output (HO) and very high output
(VHO). Most people with fish-only tanks stay with NO lamps. Both HO
and VHO lamps require special ballasts, are more expensive than NO
lamps, and need to be replaced more often (more $$).

One critical item in a saltwater tank that doesn't really fit into any
of the above topics is that which sets it apart - the marine salt.
There are many different brands of salt on the market, all of them
being basically the same. The only difference among them is whether or
not they have nitrates and phosphates. Both of these are very bad for
aquaria, so salts which have them must be avoided. Good salts include
Instant Ocean (IO), IO Reef Crystals, and Coralife. As a note,
standard rock salt can not be used as a substitute for marine salt
mixes. Rock salt does not contain the important elements that marine
creatures need to survive.

To measure the specific gravity of your saltwater you will need a
hydrometer. There are two basic types of hydrometers available to
hobbyist, the floating kind which usually measures temperature as
well, and the plastic kind with a floating arm. It's basically a toss
up as to which one to get, but the plastic kind has a larger scale and
is easier to read.

The final component needed to run a successful saltwater aquarium is
test kits. In order of importance, they are pH, nitrate, phosphate,
alkalinity, nitrite, ammonia and Calcium (for reef tanks, the calcium
test kit is more important than nitrite and ammonia). A good pH test
kit is critical, and an electronic pH monitor is even better. Ammonia
and nitrite tests are only needed occasionally after cycling. A
nitrate test kit is a good overall test for water quality after the
tank becomes established. You should perform a pH test once a week and
a nitrate test every two weeks. The other kits are not necessary, but
may be needed to solve particular problems or after you advance to
more delicate creatures.

Continue to:

• prev: 02 The Basic Parameters
• Index
• next: 04 Setting Up