DC-901750-1.2, Duracast 1700 Gallon Plastic Water Tank | 901750 Storing water is easy with Duracast’s plastic water tanks. These rotationally molded tanks are made with FDA-approved polyethylene resin so potable water stays safe to drink. Black and green colored tanks slow down the growth of waterborne algae and help to keep the water fresh. Equipped with a 16-inch vented manway fitting, you can fill up these tanks without spilling. Also featured on these tanks are measurement indicators that quickly tell you how many gallons of water are in each tank. People can use these tanks to keep a temporary water supply or for farming, irrigation and construction purposes. This is a 1.2 specific gravity tank.