I encountered the exact same problem. I have an established 75g with Oscars and one day i wake up to everything brown. I put some phosphate that come in the pre sealed bags into my Emporor 400. I did some water changes and I removed everything that had the alge and cleaned them by hand. So far so good...My tank is aswell near a window and yes the problem is caused by too much lighting.
Hope I helped. If you wanna ask me anything I didnt write then PM me.
Hope I helped. If you wanna ask me anything I didnt write then PM me.
