I don't know much about them, I am just getting going good with them myself. The way I understand it is they just need simple low water movement with good stable readings. I have one live caught (make sure eating before buying - lots of them won't eat) that I am caring for now and he is doing great. I am expecting my first 2 tank raised guys tommorrow. My wild one will only eat LIVE brine shrimp and molly/guppie fry. I was told that her seeing the tank raised eating the frozen mysis would help her learn to eat the frozen. I have a freshwater tank that I breed fry to supliment buying guppies and brine. I have mine alone other than a lone crab and snail in a 20gal tall. I understand that starfish can sometimes attack the horses since they move so slow and that fast fish worry the seahorses and will cause them to starve cause they eat so fast and the horses study food carefully before eating.
I would like to see someone with more experience respond to this too, as I am gathering all information on the subject I can find myself.