DC-900850-1.2, Duracast 850 Gallon Plastic Water Tank | 900850 When you need to store large quantities of water, use Duracast’s 850 gallon plastic water tanks. These plastic tanks are perfect for storing water and have several important features to make them your No. 1 storage choice. The polyethylene resin is FDA approved so that you can store potable water safely. The resin is also UV stabilized, which means these tanks are long-lasting even when kept in direct sunlight. The green and black colored water tanks are more effective at blocking out the green spectrum of sunlight, which helps slow the growth of waterborne algae. Low maintenance, these storage tanks are easy to clean just by accessing the 16-inch vented lid. These tanks are also equipped with gallon indicators molded into the tanks so that you can determine content levels at a glance. People can use these tanks to collect rainwater, keep their yard looking green, store an emergency supply of water, or to have a fresh supply of spare drinking water. This is a 1.2 specific gravity tank.