While we have seen water last for many years in this type of plastic, the suggested rotation schedule is as OFTEN AS POSSIBLE. If you happen to be one of the 90% of the people who simply forget, your water will be safer for longer with a WaterPrepared tank because of the high-quality, non-porous plastic that our tanks are made out of. WaterPrepared helps make rotating water convenient by allowing you to hook a standard garden hose up to your tank. With such convenience, we suggest using your water to rinse cars, water flowers, fill buckets, and in any other situation to ensure that your water is regularly being turned.