Specially selected bacterial strains in Pond Zyme;with Barley;immediately begin breaking down fish waste and dead algae that cause cloudy water, sludge build-up, and debris that clogs pumps and filters. Through enzymatic action, Pond Zyme with Barley reduces pond maintenance and keeps pond water clean and clear. Pond Zyme with Barley is a 100%-natural product, safe for all pond fish, plants and wildlife.