I did this multiple times. At first I tried a copperband as big as my tangs which I had was a yellow,clown and a naso all about 4-6in each in a 180 and the copperband did well but the yellow hated him and you could see it the copperband was able to toughen it out and ate frozen food extremely aggressively as I train my copperbands to eat frozen before releasing them into the tank. They are always put in an acclimation box so I can target feed them from live clams/mussels to frozen. Then my new one I actually added a new tang at the same time. The copperband was smaller a lot smaller at about 3\in while the rest of the tangs including new one is about 6 inches. The new tang powder blue was able to take a good beating and I felt comfortable releasing the copperband within a few days as I got it to eat frozen my second day of having it. So far copperband looks good not nearly as many aggressional issues as the first copperband. Hope this helps.