I'm in the process of changing my 34g solana into a frag tank. Right now the tank is BB and the frag rack is outside drying. My question is do I have to have LR in the tank? It has a sapphire protein skimmer in the first chamber, LR rubble and carbon/gfo in the second chamber, and the return pump and top off in the third. I plan on doing 5 gallon water changes every week. I have plenty of LR I could use in the tank, but I would like to keep it clean.