My fish only is a 300 gallon pond with a 150 gallon capacity sump and a 60 gallon refugium that houses currently 3 urchins (I know, it's not a fish only anymore, but they've been banished and I don't want to just kill them) in the refugium with an undulated trigger (I know, I know, same thing, but he was a rescue project and he's really cool), and a California Bat Ray in the 300. He'll eventually get a companion and a couple of bonnethead pups if I can ever find them, and also eventually move into a larger pond, but that's my fish only set up for now. Knowing me, as soon as I put the MH lighting over it, which I will do tonight I think, I'll start throwing corals in there and it'll be a reef with a bat ray and sharks....