I just bought two copperband butterfly fish. One for my 300 and one for my 90. I have nothing but peaceful fish in my 90 so that one is fine, but my emperor angel was chasing and nipping at the copperband in my 300. We caught it because I knew my emperor would kill it. Can I add two copperbands to the 90 until I can return one to the fish store tomorrow or will they fight? Should I just float the copperband in the sump overnight? It's currently back in the bag.