Glowfish;703074 wrote: 12 gallons is way too small for the larger seahorses in my opinion, b/c their bioload is way too big for a tank that small (they require frozen mysis 2x a day). Everyone on the seahorse forum (seahorse.org) would agree with me too. That kind of tank would also heat up too easily in the summer which would could cause a vibrio outbreak when the water reaches over 78 F and the seahorses would probably die. You could try a smaller species like fuscus seahorses, but they are almost 100% impossible to get, b/c of importing permits. The only people that I know with that species cannot get their pairs to breed.
I would really try to get a tank that's at least 20 gallons and try to have LED's or lighting that would give off less heat for the summer situations.