Non-foaming, non-metallic, prevents green, black and mustard algae. Specifically designed to prevent the growth of algae in swimming pools and ideal for pools with attached spas and water features. Should be a part of your regular maintenance program to prevent algae. Weekly addition of this product will reduce overall maintenance costs and give you water quality you desire. The product of choice to help keep your pool algae free. Most popular is the 32oz size!