DC-902200-1.2, Duracast 2200 Gallon Plastic Water Tank | 902200 With Duracast’s plastic tanks, water storage is both safe and convenient. The FDA approved polyethylene resin means that you can use these tanks to store potable water. Green and black tanks keep your water clean and combat the growth of waterborne algae by blocking out the green spectrum of light. Tough and resistant to many physical attacks, these tanks stand up well in a various environments. Lightweight, these tanks are easier to transport than bulkier, heavier alternatives. The 16-inch vented manway fitting allows you to fill these tanks quickly and gives you access for cleaning. Measurement indicators are molded into the plastic so you know how many gallons of water are in each tank. This is a 1.2 specific gravity tank.