I have used Copperband Butterflies on two different reef tanks. Both had very bad infestations when I added the CBB. In my 140 right now, I have one that keeps the display tank spotless of aiptasias. They are still all over in my overflows and sump, but there are none in the display and hasn't been for years. The only thing I have seen the CBB mess with are feather dusters. I can live without feather dusters.