what size tank? It can be a too small due to their dietary needs. And remember that you won't be able to have much of a flow, seahorses cannot have too strong of a flow.
Check out www.nano-reef.com or some of the other nano sites. Seen people have set up 12g nano's with seahorses that were running for 5+ months.
24g should be more than enough.
edit: Do some research, i'm no expert in seahorses but have seen successful tanks with seahorses + coral so take my word of advice with a grain of salt.
I have a seahorse setup in my 12gallon running for about 3months now. Their doing great. Took out the pump in the nano and added one with less gph, some zoos and polyps, 4 reid seahorses and dead coral branches for them to grasp on. I built a refugium in the second chamber for the nano and do a 2liter water change every 2-3 days. 3 months isn't long but I've my seahorses are happy. They like to be fed throughout the day. I feed them live brine shrimp in the morning, afternoon and before I leave the office. So your 24 gallon is more than enough. Just don't overstock Like I did or you'll be doing water changes quite often. Hope this helps..
I've kept two emperor seahorses on my desk at work for 4 years in an 11 gallon, tall tank. It should be fine. Be sure you figure out feeding (mine are tank-raised and eat frozen mysis).
Mixing stinging corals and seahorses may not be such a great idea, though.
I don't see any problem with keeping seahorses in NC24. However, if you research about the seahorses, they are mostly require low temperature to keep them happy. For my experience, it's really hard to keep NC tank to low temp. If you can keep your tank temperature low, I think NC24 is great looking tank to keep seahorse.
i have a trio of reidi in a 40br and was thinking of upgraading to a 65g.
a 24g can accomadate dwarf seahorse but you must remember that dwarf seahorses depend on live food. a 24g is not large enough to sustain a good amount of live food so it will most likely mean that you will have to buy live food or culture it somehow.
Tank height: 20 inches minimum is recommended
Tank Volume and Stocking capacity: 10 gallons for 2 to 4 individuals, 25 gallon for 4 to 10 individuals, 55 gallon for 10 to 15
100 gallon for 15 to 25, 150 gallon for 20 to 30
Are you talking dwarves (zosterae) or larger breeds (erectus, reidi)? For dwarves, a 24 will be huge. You could never get enough baby brine in there for them to eat efficiently. I had 8 in a 3 gallon eclipse for a while. For larger species, a 24 should be good.
I have a black seahorse (caught locally) in a 3 gallong eclipse tank. Water changes are done from the "dirty" water, on my water changes from my 120G. This seahorse eats anything.....flakes, big frozen mysis, brine etc. This is actually my first time keeping a seahorse but it seems pretty healthy.
24g should be plenty big enough for quite a few species, and indeed too large for the dwarf species. Seahorse.org is a good resource for tank parameters too.
Temp--yes, some species (Cape seahorses for example) are temperate and need room temp water, nothing above 72 (though I had good luck keeping SH fry slightly higher). If you choose a temperate species, you will need a chiller if it is kept somewhere not climate controlled, but there are "microchilelrs" available that are small hang-on units. Other speices are decidedly tropical and will need typical reef temps.
Definitely be careful about which corals you choose. No anemones, no stinging ones, nothing that has long feeder tentacles. Xenia is a good choice. I see many tanks with Gorgonians, though I have not used them. And make sure to have plenty of appropriate safe "hitches" for the horses to hang on to.
Feeding--the dwarfs will need live food (BBS). Other than that, do yourself a favor and wean your horses onto frozen or other. For the small guys, frozen cyclop-eeze or (better) grated mysids are good.