3P Technik 210 Gal. Light Granite Jumbo Rain Water Tank-9000128 - The Home Depot. The 3P Technik Jumbo Rain Water Storage Tank is a high capacity option for your above ground rainwater storage. These modular wall tank can be connected together with a 3P Technik Connection kit, allowing you to store as much water needed for any home, business or municipal use. With a slim shape, smooth surface fit and huge capacity of 210 Gal.