You're right to worry about the Copper Band.Those can be difficult to keep -period. Does yours go after the frozen food ? If so consider yourself lucky,lol. If you can't cut back on food maybe you could try adding a few more corals for natural nutrient control.Preferably something that would eat the critters unfortunate enough to get near them. A Euphyillia comes to mind.Provided that the parameters are stable enough for more corals. I might just be making excuses for you to buy more corals though.