I dosed this for a few weeks back in the September timeframe. Seemed to thin out the algae after a few doses but I also noticed that my LPS didn't look amazing while dosing. My hair algae has continued to be a huge problem, so I'm back to dosing Algaefix while I run heavy GFO and do many water changes. I need to get rid of this algae! I have a "3D" rock back wall and it is just absolutely covered in GHA (along with other stuff, so its not just something leaching out of the wall). I use RO/DI only, oversized skimmer, biopellets, GFO... still tons of hair algae. I see zero nitrate and don't feed too much for my 180 gallon, as far as I know. Man... I just want to have a nice clean tank.