Cleaning Chemical, For Use In Lakes, Ponds, Water Gardens, Treatment Coverage Up to 5 acre-ft, Usage pH 5.5 to 9.5 pH, Container Type Block, Container Size 5 lb, Formulation , Enzymes, Shelf Life 2 yr, Reapplication Time 60 day, Non-Toxic Yes, Cleaning Functions Dissolves Sludge, Removes Dead Leaves and Grass, Features Improves Dissolved Oxygen Levels, Increases Water Clarity, Reduces Ammonia and Nitrogen Levels, Significantly Reduces Noxious Odors Caused By Hydrogen Sulfide, Form Block