Specify a Grp Water Tank is used to provide group water for firefighting training and other purposes. They are made of polyethene or polypropylene and have a plastic liner, usually with an antifreeze additive so the water stays cool. Grp water tanks can also be steel or fibreglass lined. The type of grp water tank you need depends on whether your application is seasonal or year-round, and where you plan to use the tank. A seasonal grp tank is generally used for fire training, while an annual gr Pak is used for year-round applications. For example, a seasonal grp tank is ideal for fire training in the summer when it’s not raining; however, it can also be used as an annual supply tank during the winter season when it’s raining.