I used new media and the metal halide bulb was changed about 6 months ago, but I have never changed the T5. Do you think it would be a bad idea to put the corals into the 120g. When I get home tonight I will take a picture of the tank and post it so you will have a better idea of what the brown algae looks like. It is almost stringy and hangs off of the corals and just today has started to cover pretty much the entire sand bed. Sorry it's just so frustrating to not know what is wrong with the tank, I just want to fix it.