I have BBA mostly where my flow is the strongest. I have tried just about everything and cant get rid of this crap. I've been doseing with Excel 3 X the dose every day for well over a week. It slows the growth down but there it's still on my plants and now on my substrate. I have to clean it out from my water outlet all the time. I have pretty strong flow also. Eheim 2026 on a 55gal.