We were starting to get that problem 2 years ago. The FA was taking over and I did not want to use chemicals to kill it as we swim in the pond and so do our dogs. At the suggestion of my pond man, Scott Trava (http://CatskillPond.com) Last year in late May once the runoff stopped we used pond dye for the first time. Between that and aeration we had no FA at all last summer.
This while we had a severe drought that brought our water level down at least 2 feet from the spill way. I planned to do the same thing this spring and hope for the same success against the FA.
