the fish thing depends who you talk to, many non-aggresive fish can work. excellent fish for seahorses are gobies, cardinals, dartfish, and stuff like that. corals just need to not have stinging tentacles. gorgs are useful holdfasts. zoos, leathers, and some sps will work. clams are not good, they can clamp tails, but most softies and sps are good. most lps have sringing tentacles. o ya, NO ANEMONES!!!!! have fun!