Tropical Sciences makes phosphate pads specifially designed for removing hair algae and cyano. I bought a pack that contained 2 pads, and a powder substance and it worked fine. Also, do you have a canister filter? I had a Fluval 404 hooked up until last night & I finally took it off. Lots of poeple say they are nitrate factories, & at first I didn't believe it, but now I do. Ever since I've had it unplugged, which has been for a week before I took it off, the red slime went away.