went through some of those, cut back on feeding, don't use frozen foods, try not to use flakes. i am using daikinichi pellets. get the mag to 1600 and maintain for a while, do not do water changes, give the mag time to work.just maintain it, clean as much algae as possible, use a turkey baster to suck it up. keep the glass clean. do not use a filter sock, it clogs in 48hrs, and will help with the algae growth. (all from my experience) if the tank is recieving light from the sun through a window, cover the window with curtains. natural sunlight in our tanks without a uv filter will speed up algae growth. I have to clean my glass every day, green algae on glass where the sun hits it.
hope i'm not rambling, writing as i think.