Item #30112 - 16 oz.Treats 12,000 gallons Item #30113 - Gallon A non-toxic coloring agent that will make your pond water a beautiful lagoon-black. It will not harm or discolor ornamental aquatic plants or fish. As a benefit of its color, Pond Shade reduces the amount of sunlight (UV light) that penetrates the water, making it an ideal non-toxic deterrent to green water.