Chances are that grouper grows up and starts wreaking havoc. I put a small louti grouper in a fish only tank with about 6 other fish (tanks, wrasses, clowns, etc.) that I had about 10 years ago. The guy at the LFS told me he would be fine if I "kept him fed"......I believed it :tongue: 1 year later......I had a grouper only tank. Most adult groupers will not tolerate any other fish in their tank, I've tried it twice, even with the most "docile" of grouper species....and my experience has been if they can't eat it they will kill it, If they can't kill it they will die of stress.