[xoomer]

I've seen people paint the back of the tank but I've always felt it's not the cleanest, although I've seen some decent jobs when people pay attention to details. I myself apply black adhesive vinyl to my tanks and it looks sharp, the vinyl is resistant to saltwater and it will stay on the tank for years without any problems. It can be removed easily if one desired and had access to the back of the tank. The truth is that withing couple of years most of the background will not be visible because of coraline growth in a normal reef environment.