The AquaSphere PRO treatment system is for larger ponds up to one acre. The 10 1/4in. disposable/recyclable plastic sphere is preloaded with a natural bacteria and enzyme blend, designed to treat the real problem of ponds and lakes: excess nutrients. Patented time-release system meters daily doses of bacteria and enzymes that help keep sludge and algae blooms in check. Commercial applications include golf courses, commercial real estate, homeowner associations, retention ponds, parks, zoos, recreation facilities and fish hatcheries. Safe for humans, pets, fish and plants. U.S.A. Treats 1 acre (about 1,000,000 gallons) Treats water for up to 30 days Effective in water temperatures between 34°F and 110°F Rids water of excessive organic nutrients Reduces sludge layer Reduces offensive odors Model 91100