hey im a noobie here at this stuff and i need help. i have set up a 120g tank and hooked up a fluval 304 and marine canister 350 magnum. the water keeps turning brown and i have the water polisher. i have a 55 gallon glass tank and i want to turn it into a filter and i dont know how to do it with glass tanks. can anyone help me out? i will post pictures of the items i have