[JandC]

Since we just bought our Montana I have not utilized the fresh water tank yet or stored water in it. But based on our experience with water tanks in larger boats, you need to rotate the water out of these types of tanks. In the marine environment it depended on the quality of water you filled the tank with and the outside temperature. In hotter temps the water just does not stay fresh as long. As someone else mentioned, a little bleach works or adding FreshWater additive helps.