I had a pair of True Percula's in a 50g with 2 PJ Cardinals, 2 Benggai Cardinals and a blenny. Everything was great for a while. I have to believe this tank provided more than enough room for these fish. They all seemed to eat properly and I fed them regularly. All of the sudden, the larger clown (they were both the same size when I purchased them) attacked and killed both Benggai's and the smaller clown. What the hell happened? Any ideas? I think he needs to go back to the LFS.