I can't believe it but this product REALLY works. I have 4 100 gal Rubbermaid water troughs for my horses and they are all out in the sun. They usually get slime and algae and need to be pressure washed and scrubbed but not with this product....Water stays clear and no scrubbing necessary. Just a quick swish with the hose and good to go. Many thanks for a super product, I will not be without it!