I am about ready to throw it all away. I dipped all my plants, cleaned everything and now after about 2 weeks, maybe it is three, that nasty stuff is coming back. I change water once a week about 15 to 25%. I am thinking that maybe my tap water has junk in it that this algae likes. I also think that maybe I should be adding fertilizer to the water so the plants can giddy up and grow. Maybe this will help out compete the algae. Tank is a 55 gallon with 174 watts of light. I think I need some major help.