I have a percuka clownfish in a 55 gallon tank with live rock cycled and all the water perameters are correct. He is about 2 and a half or 3 inches. He was fine but when I put a butterflyfish In there he got very aggressive I had to move him to a 30 gallon tank alone so that he wouldnt kill the other fish. What can I do what can I put in there for tankmates? Thanks for your help