greetings ! I have a large Pond that is Rain fed , approx. 15,000 gals. I have many Goldfish that Winter over and have new babies every year, a snapping turtle or two that unfortunately keep it muddy looking, not sure, and crawfish. Up until a couple Years ago it was problem free . Now I get Algae every Summer. There are days when it covers the whole surface, but most of the time due to winds it will settle across half of the Pond. Can anyone tell me what would be good to treat it with that is natural? I thought of throwing in some Anacharis that I have growing in my indoor Aquarium. I don't have any filtration system in the Pond and because of its size it would be impossible to install now. Any tips would be appreciated .