Crystal Plex Algae Control Step 3, 1 Gallon is a highly effective liquid copper sulfate solution designed to control various forms of algae in your pond. This product remains active for up to 30 days, providing long-lasting algae control without irrigation or consumption restrictions. It is safe for most fish species, making it an i choice for maintaining a healthy aquatic environment. For optimal results, apply using a broadcast spray and treat only a portion of the pond at a time to avoid oxygen depletion. Please note that this product should not be used in Koi, Goldfish, or Trout ponds. The ready-to-use 1-gallon pour container covers up to 1 acre with water depths ranging from 1 to 3 feet. Model Number: