PondCare AlgaeFix Algae Control for PondsAPI Pond AlgaeFix effectively controls many types of algae in your ornamental pond, water garden, or fountain. This safe, effective water treatment removes Green or Green water algae (Chlorella), String or Hair algae (Cladophora) and Blanketweed (Oedogonium). #1 algae control product for controlling green ponds and green algae Keeps Koi ponds and goldfish ponds and water gardens clean and clear Controls existing algae and helps resolve additional