Specially selected bacterial strains in API® POND-ZYME SLUDGE DESTROYER bacterial cleaner immediately begins 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 SLUDGE DESTROYER bacterial cleaner reduces pond maintenance and keeps pond water clean and clear. It is a 100% natural product, & safe for all pond fish, plants, and wildlife.