I have a 75 gal. Its 18 months old. Within the last 3 months, I am getting this brown hairy stuff all over. Water temp. is 79 F. I have 6 T5's 3@10,000, 3@ Actinic. The 10K's are on 10 hours a day.The Actinic are on 11 hours a day. I have an Octopus needlewheel skimmer, I have a RO DI system, I...