I increased mine to 2@33Watts CFL. This seems to produce a very dark green instead of brown, so its on its way. I am thinking I might go to the 44W CFL's I seen at Walmart for about 10 bucks each if these 33W's do not get green in a few cleanings. I also found better [color=#00BF40]green[/color] results if I just scrap the algae off and not spray it clean with water pressure but just rinse it after the scrapping.