[edikpok]

In my 29 biocube, I have a mated pair of black clowns, bangaii cardinal, midas blenny and a 6 line wrasse. They occasionally fight but are overall happpy together. Most fights start when others are getting underneath the open brain under which the clowns live....weekly 5gal water changes

As others said-3 clowns might be problematic. As 2 of them decide to mate, the 3rd one will have to go. Hard to keep more than 2 in a system smaller than 50-60gal

If you get a firefish, make sure you close the opening between tank and filter compartments. I cut out a piece of plexiglass for that...these fish are darn good jumpers and in a company of clowns, they might try to bjump out.