my phosphates and nitrates are high, my main issue was what to do to try and wipe out what is already there, yes I know lowering these levels will help stop new growth, but will it kill out whats already there or just slow it down but it will still be present. It seems to me that once the stuff is rooted in, you can scrub it away and it will still eventually grow back until you pick and scrub it again, and again, and again....