Sludge accumulation in a pond occurs for a variety of reasons. Leaves and grass clippings can be blown into the pond. Droppings from animals such as fish, ducks, or geese can sometimes be significant. Even over-feeding the fish in the pond can promote sludge accumulation. In many ponds, the largest contributor to sludge build up is dead algae. Every year, algae populations increase to at least some extent during the warm sunny months. These algae die off, and then become part of the sludge accumulation. Dose the pond with one ounce of Sludge Digester for every 1000 gallons of water (note: 1000 gallons = 135 cubic feet). Repeat this dose at least once a month, and as often as once a week. But do not dose sludge digester more often than once a week during the pond season.