I fight this stuff continuously. I have started wading out with one of the rakes I purchased from one of these sites and I try to contol one side of the tanks I want to fish. You can not do all sides especially on one as large as yours. The Cuitrine Plus granules works the best for me and I have broadcast whole ground corn meal , which may help. I did not see drastic results with the corn meal. Anyway, pulling out as much algae as you can handle, then treating with the Cutrine Plus seems to work the best. From what I can gather if you get a bloom ahead of the algae it will help contriol it, but the problem is it forms before the temps get to the point that everyone says to treat with fertilizer. Good luck and if you find a permanent solution e-mail me at [email protected].