My tank has been getting more and more green over the past couple of weeks and now I can barely see through the water! Little info, 90 gallon with two external filters, heavily planted (all plants growing great), 120 watts of T8 lighting on for 8 hours per day, no sunlight reaches the tank at all, 50% water changes weekly and then liquid ferts added, fish fed once per day.. Not sure if I've missed anything but how do I get rid of this? I have 4 other tanks and they're all crystal clear! There's no algae on any surface, just green water!