Hi Robert. In order to keep hair/blanket/string algae and suspended algae away from ponds, the trick is to have a balance in your pond either through plants or biological filtration. We've been making our own for years and our water is always crystal clear and we never have hair algae. You can find a diagram of the filtration system we use at our clubs website at: www.geocities.com/ont_pondkeper

Yours Koily, Lorraine
London & Southwestern Ontario Pond Keepers