A liquid copper sulfate used to control many forms of algae and stays active for up to 30 days. No irrigation or consumption restrictions and is safe for most fish. Best results when applied with broadcast spray. Only treat a portion of the pond at a time to prevent oxygen depletion. 1-gallon treats a 1-acre pond 1-foot to 3-feet deep. Do not use in Koi, Goldfish, or Trout ponds.