Sintex Water Tank. Sinter water tanks are easily one of the best water tanks in India.A plastic water tank is a large capacity container designed to store water for household, agricultural, irrigation, and industrial manufacturing use. The varieties of plastic water tanks range from ones that can be carried and placed in a truck to ones that can hold thousands of gallons of water and be buried.Due to the fact that they do not react with the food or substances they contain, plastic containers are utilized as storage devices. So, they are safe and convenient. Metals are not used as storage for lengthy periods of time since they react with other food substances while plastics are non-reactive.