DC-901600-1.2, Duracast 1550 Gallon Plastic Water Tank | 901600 These rotationally molded tanks are manufactured following strict industry standards so that you can enjoy long-lasting quality. The polyethylene resin is FDA approved to ensure safe potable water storage. The resin is also compounded with UV stabilizers to provide even more years of usefulness. Manufactured to be kept both indoors and outdoors, these plastic water tanks are durable and will not break down easily from harsh environmental conditions. Green and black tanks are designed to block the green spectrum of light and are more effective at slowing the growth of waterborne algae. People can use these plastic water tanks to collect and conserve rainwater, for irrigation purposes and to keep spare drinking water. This is a 1.2 specific gravity tank.