i just got my oceanic 180 gal, (with overflows) and my amircale Maxi-reef 400 W/D. i think i have a pretty good grasp on what to do, but i was told it would be a good idea to install a ball valve on the inlet hose from the overflow. my filter actually has 2 separate towers of bio balls, so one hose from each overlfow runs to its own "tower" of bio balls. i went to Home depot and looked at their ball valves and adapters and found what should work. dont i need to glue all this together? will pvc glue be toxic in my tank? the return line from my pump i'm guessing i will just use flexible clear plastic tubing. any suggestions?