We put in an Aquascape pond kit for a client a while back. The project turned out beautifully, and the client was happy. Suddenly though, she has been having string algae problems. We have tried Algae buster, and even drained the whole thing and cleaned it. The string algae continues to crop up! She also has koi, and they are apparently not doing the algae control thing either. She wants us to get some fish that will eat string algae- any ideas???