TFH Archives
two cats in a duffel bag because there’s
simply no way for each to escape the
other’s line of sight.
Again, this isn’t an attempt to
dissuade you from keeping a clownfish
or damsel in a smaller system (with
the exception of really small nanos,
which I would discourage), just to
apprise you of the limitations of small
systems and the special challenges
they present.
Some of the smaller clownfish, such as ocellaris and percula clowns, will do well in a nano
aquarium.
Many of the pomacentrids are good
candidates for reef systems, being
relatively small fish that won’t eat
corals, anemones, or other desirable
invertebrates.
Water Quality
A modest amount of evaporation results
in a significant increase in specific
gravity in a smaller system. So forgetting
to perform a freshwater top-off—even
for one day—could cause a precipitous
rise in specific gravity and have a very
adverse effect on the well-being of the
livestock in a nano system.
Additionally, any contaminants, such
as soap or lotion on your hands, that are
accidentally introduced or additives that
are accidentally overdosed are much
more concentrated in a smaller volume of
water than they are in a larger volume.
Lack of Space
Furthermore, the smaller the aquarium,
the easier it is to overstock or stock
inappropriately. Giving in to the impulse
to add “just one more specimen” can
tax the biofilter in a system of any size,
but in a small system, yielding to this
temptation can have a disastrous impact
on water quality.
Ttueni/Shutterstock
Small Pomacentrids in Big Tanks
Introducing a very small pomacentrid to a very large tank can pose certain husbandry
challenges that won’t necessarily present themselves when the specimen is in your
quarantine tank. These challenges might include certain dangers that weren’t an issue in
quarantine and that are never experienced in nature. For example, a diminutive damsel can
easily be swept into the overflow chamber of a wet/dry biofilter or get stuck on the intake
of a powerhead. Any such hazards must be blocked or screened off to prevent accidents.
The high level of water movement that is necessary in a large system can also create
problems for a small pomacentrid. Constantly struggling against a very powerful current
can exhaust a little damsel or clownfish—potentially stressing it to the point of death. Also,
feeding small pomacentrids is more of a challenge in a larger system because the brisk
water movement can quickly disperse small food items before the damsel or clownfish
sees it. To mitigate these potential problems, it’s helpful to provide an area of slack current
in the aquarium where the clownfish or damsel can rest and take refuge. To prevent
tiny food items from dispersing too quickly, it’s a good idea to temporarily unplug your
powerheads and pumps at feeding times.
Just Right for Reef Tanks
Corals and other sessile
invertebrates are the priority in
any reef aquarium. The number
of fishes is often kept low in order
to minimize their impact on water
quality, which must be topnotch
in a reef system, and any fish
specimens that are introduced are
chosen for their compatibility with
the invertebrates—i.e., they don’t
include sessile invertebrates as part
of their natural menu and they aren’t
heavy polluters. Many clownfishes
and damselfishes satisfy these
reef-compatibility requirements
superbly, being generally small in
size, producing minimal waste, and
usually being inoffensive to sessile
invertebrates.
94
www.tfhmagazine.com
October 2010
