Here is my General story, if questions arise, I'll answer, I'm going insane. I have 125 gal display and 55 gal sump/refugium. For the past 2 months I have been battling green hair algae, I have gone through 2 major water changes, I have scrubbed the rocks and been clean for days, then the hair is back. I test 0 on phosphates, I grow Chaeto in my sump, it's doing fine, I have reduced my lights to be bright for 3 hours when we're at home and can appreciate the tank, I run very low lights during the day. I'm going nuts, help!