Ginesis Sludge Pellets - Natural Water Treatment for Water Gardens, Gof Course ponds, Fish Ponds, Ornamental Ponds, Koi Ponds, and Small Lakes. Safe for fish, pets and humans. 50 pound bag. Improves Water Clarity Breaks Down Odor-causing Muck on Rocks and Water Features Reduces Sludge without the need to drain Water Gardens Convenient 3 in 1 spot treatment product Safe for fish to ingest