I've been having problems with bottle brush algae so I started using excel. I'm not overdosing, just using the recommended dosages. It seems to be clearing up but I had 3 large snakeskin val plants that have totally withered and I'm not sure if it's the excel or not. I just medicated my tank for ich at the same time I started using excel so I'm not sure which one is responsible. Maybe I should cut them down and see if they'll regrow? The were so big and beautiful. I also did buy (as recommended from my LFS) a white filter that is supposed to help eliminate algae. I haven't put it in yet though.