When I fisrt got my tank I was planning on an SPS tank and I bought two pieces of, I will call it, fake rock, probley some sort of something that at one point was a liquid mixture of something that was poured into a mold to left to harden. The two pieces are I would say are about alittle over an inch thick and flat. My plan was to put these at the top of the tank and to mount some tabling Acropra to the top of these two rocks. My plans have changed and now I will have a Zoa and polyp tank and a few months ago I took one of these rocks out of the tank and its sitting in my shed. Before I took the rock out of my tank it was starting to color up nicely along with all the other LR in the tank. My question: I now have decided I want to put this piece of fake rock back into my tank and to mount polyps to it as I have done with the other piece of fake LR that I didn't take out of the tank. Do I need to take a wire brush to this piece of fake rock before I put it back into the tank, when I do put it back into the tank, will it cause a problem to either my fish or my polyps that I have in the tank? It seems that most of my polyps do better the closer they are to the lights in the tank and I want to put this rock back into the tank because its flat and I can mount alot of polyp frags to it and keep them close to the lights. Any thoughts on this. I just don't want to hurt anything I already have in the tank.