This blend of live bacteria & enzymes is specifically designed to improve water quality by reducing unwanted nutrients in your water. It clears out pond- or lake-bottom debris like leaves, grass clippings, dead & dying plants, excess food & other organic matter. These bottom-lying materials are referred to as the sludge layer & are responsible for Bad odors & low oxygen levels. Each 5-lb. Block treats up to 5 acre Of water. Non-chemical treatment is safe for fish, plants & other wildlife. U. S. A. Treatment capacity (gal. ): 1, 629, 257, material type: bacteria, enzymes, compatible with: 5 acre. Pond, : Yes, Includes (Qty. ): 1