Pond was built about 4 years ago and is about 1 acre. I have my sand filter that runs into the pond so the nutrient load is very heavy. I have 2 questions, first what kind of algee is this and also i was considering putting in a holding tank for the sand filter water to run into and then pumping it over the hill. I guess its a crazy idea but I cannot control this in the summer time as I have been using cooper sulfate along with blue dye with minimal results. I also have 3 grass carp that I put in about 2 years ago.