While it's obvious that a 12" Elegance coral is not
going to be particularly happy in a 2.5 gallon aquarium, it can be a little more difficult
to figure out which animals will do well in such an environment. This section of the
website is devoted to discussing the different animals which can be kept successfully in a
Nano or Micro. It will also mention some animals which shouldn't be kept, as
some of them may seem entirely feasible upon first inspection.
Micro/Nano Keepers: your input here is actively solicited.
I want to hear about your experiences with different animals in your micros/nanos. Please email me with any information you can provide, wether it
concerns a success or a failure.
Mandarins - many people think they can keep a mandarin in a micro or nano successfully, since the live rock will provide plenty of copepods for their food, and the absence of other, more vigorously feeding fish seems to make the nano the perfect environment. Sadly, this is NOT the case. A small tank simply cannot produce the numbers of copepods required to maintain a mandarin in the long term. If you can provide copepods and such from an additional source (say, from a refugium attached to a much larger reef tank) then it should be possible to keep a mandarin in a nano. Otherwise, don't attempt it -- you'll just be condemning your fish to an eventual slow, lingering death of starvation.
Fish which I have successfully kept in a nano include
percula clowns, ocellaris clowns, maroon clowns, dominos, royal grammas and banggai
cardinals.
Euphyllia (Hammers, Anchors, Torches) - all three of these corals can be maintained in a micro or nano, providing a few criteria are met. Strong lighting is a must, as is keeping these corals well seperated from any other species of corals in the tank. All produce particularly long sweeper tentacles which can severely damage other corals. The different species of Euphyllia can be allowed to intermingle without harm, however -- and a tank of mixed specimens can look absolutely stunning.
Bubble Corals - the various bubble corals, like the
Hammers, produce long sweeper tentacles. Small specimens make excellent inhabitants for a
nano, though, as they require comparatively low light and current.
Elegance - since even small specimens can expand
enormously, this is another coral that pretty much has to be kept on it's own in a nano.
Some clownfish will accept Elegance corals as surrogate host anemones, however, and a nano
with a good looking Elegance and matched clownfish makes a nice display.
Acropora species - I have not attempted to keep any SPS
corals in a nano, but I know of several individuals claiming success with these corals in
tanks as small as 2.5 gallons. As is typical of SPS corals, lots of current and very
strong lighting are required to keep Acropora successfully. I would imagine that if you
could purchase 3 or 4 small Acropora fragments of differing colors, you would have a
jaw-dropping tank if you're successful in their keeping.
Colt Coral - one of the easiest corals to keep because of
it's wide range of adaptability, Colts make great nano inhabitants with only one drawback:
they grow, quickly. If you choose to keep a Colt in a nano, you will most likely have to
take cuttings from it often.
Star Polyps & Button Polyps - these animals are very
common in nano tanks, due to the ease of keeping them combined with their small individual
sizes.
Mushrooms - another very common nano inhabitant are
mushrooms. Colorful, easy to maintain and quite likely to propagate in a healthy
environment, mushrooms have long been a standby in reefkeeping circles. Their
comparatively low-light requirements are another excellent reason for their inclusion in a
nano.
Xenia - I personally don't know of anyone who has thus far
tried keeping Xenia in a nano. Anyone who has tried, please contact me -- I'm very
interested in hearing your experiences. A Xenia dominated nano tank would be gorgeous, I'm
sure.
According to Daniel Knop, the best tridacna clam choices for a nano are t. crocea and t. derasa. Other species will rapidly grow too large for a nano; even t. derasa and t. crocea will do so, given enough time. Both species require plenty of light, and attempts to keep them should not be tried unless you can provide them with the quantities of light they need.
I personally do not keep anemones, so I can contribute little here. I do know of a few individuals who have claimed to be successful keeping them in nanos, though, and I don't see why this wouldn't be feasible with enough light and good water conditions. Obviously, don't keep corals in a nano with an anemone, as they may become fatally damaged by the anemone's movements in such a small environment.
Turbo snails are a bit large in a nano tank, but they do a much better job of eating algae then their miniscule brothers, the astrea snails. A little underwater epoxy will add stability to your rocks and corals, allowing turbos to be used. If you must use astreas, use more then you think you need -- after all, there isn't much more exposed glass surface on a 5 gallon then on a 2.5, or on a 10 gallon then on a 5 gallon.
Small serpent stars are feasible, but it must be mentioned
that many are opportune feeders; if they get the chance, they may consume other small
animals in the tank. And in a nano, it's often impossible for an animal to escape by
running away.
Blue leg or scarlet leg hermits make excellent additions,
and should be considered indispensible.
Sea Cucumbers should be avoided at
all costs. When they get distressed or die, they release some very toxic compounds into
the tank. With the small water volume of a nano, this means they can wipe out the tank in
an eyeblink. While they may make great sand sifters, their disadvantages in a nano far
outweigh their positive attributes.
This list is far from complete, and I hope to be able to make
regular additions to it.