Nano cubes are indeed compact and convenient, but they are not the best choice for seahorse keepers. A number of our other members have tried fairly large (24-gallon) Nano cubes for seahorses and found them to be unsatisfactory.
Other Club members who have tried the 24-gallon Nanocube for their seahorses report that it is quite unsuitable right off the shelf and requires substantial modifications in order to make it marginally useful for seahorses. For starters, the pump needs to be upgraded, it has no means of filtration so you must provide a biofilter of some sort, and small powerheads should be added to eliminate dead spots and improve the circulation. Even with those modifications, you must stock the Nanocube sparingly, be very careful to avoid overfeeding, and practiced an accelerated maintenance schedule, including weekly water changes.
As an example of what I’m talking about, here’s an exchange from the discussion forum regarding the 24 gallon Nanocube:
Hey everyone! I’ve read the posts about the experiences some people
have had with seahorses in nano cubes and I have a few questions for
them if they catch this post. I have purchased a 24 gallon nano cube
and have done alot of research on it and found out that you have to do
a ton of upgrades on it to make it suitable. The pump has to be
upgraded, there is no true filtration, you should add another power
head for water flow to elimate dead spots. Even then there isnt a
protein skimmer that you can purchase for the nano. So my questions
are where there any upgrades made to the tank? Were you able to keep
other fish alive in the setup or did you give up on it all together?
I don’t think that you should have a lot of problems and this is
why. Yes, all of my seahorses have died in a 24 gallon nano cube
setup and I have figured out why. I had a setup with sand, coral,
and two clown fish. I also had the normal cleanup crew snals,
shrimp, etc. I could not figure out why my seahorses kept dieing.
You must understand, that there should not be any other tank
inhabitants within the nano cube when you have seahorses. I would
not even advise sand. All you need is a few hitching post and
maybe, a few large pieces of liverock aligning the back of the
tank. You could add a few snails and only a few hermit crabs.
Note, the hermit crabs will clean up whatever the seahorses will not
eat. You could also add a cleaner shrimp or peppermint shrimp. You
may want to keep it a very low minimal when deciding about adding
anything else in the tank. You don’t want the seahorses deprived of
any mysis shrimp when they are feeding. You don’t want to add any
coral. Why? Because you want to eliminate any possibility of over
feeding and polluting the water. You will also want to do a water
change every week. 20% percent only, and afterwards check the Ph to
make sure it is stable.
I have 2 nano cubes. One nano I have houses
coral, two clown’s, two gobies, crabs etc. No seahorses. The other
nano is a new setup. It is about 2 1/2 weeks old. I am going to
wait about another two weeks to begin adding seahorse’s. At the
moment there are only liverock in the tank. I am not going to add
sand to this tank at all. The live rock are positioned at the back
of the tank. I want to try to leave a lot of open space toward the
front of the tank. Today, I will be adding two snails. I will not
be adding anything else but two hermit crabs only to cleanup after
the seahorses have eaten. The crabs will be added only after the
seahorses have been added. In a nano cube setup, the trick is to
not add too many inhabitants and to do a water change at least every
week or two weeks.
What you could do is add a lot of dead coral
liverock if you can find it. If not, try to find a lot of hitching
post that will work well. Sometimes you could even make them
yourself. So, I hope this has helped you and if there is any
information out there that you or anybody else have please forward
it to me because I am still learning things as I go along. [End quote]
For these reasons, I think you would be better off sticking with a more conventional aquarium such as a standard 29-gallon tall tank if you’re interested in the larger breeds of seahorses, rather than attempting a nanotank. However, it sounds like you’re quite an accomplished do-it-yourselfer, so if you would like to try a nano cube and make the necessary modifications they require for seahorses, you might be just the guy for the job! In that case, I would suggest trying a 24-gallon nano rather than a 12-gallon nano setup.
If you’re really interested in a miniature exhibit, then you might want to consider a colony of Pixies or dwarf seahorses (Hippocampus zosterae), which thrive in tanks of 2 to 10 gallons, instead of any of the greater seahorses. Pixies (H. zosterae) are widely considered the easiest of all the seahorses to breed and raise. These miniature marvels are only about the size of your thumbnail when they are fully grown and feed on newly-hatched brine shrimp from the cradle to grave. They are colonial seahorses that do best in small groups of 8-12 adults, and even a two-gallon tank is spacious enough to house a whole herd of them and all of their offspring. Let me know if you might be interested in setting up a miniature exhibits for dwarf seahorses, and I would be happy to offer some suggestions on how to create an ideal microcosm for these diminutive delights.
Best wishes with all of your fishes!