Replace the water every three to six months with new, disinfected water. Always keep commercially purchased water in its original sealed container. Generally, the shelf life is one year. Do not store larger containers, such as five-gallon jugs, for more than six months. Light can cause plastic containers to degrade, so store water in cool, dark places, away from sunlight and fluorescent lighting.
Closets are good storage spaces.
Vapors from these chemicals can permeate the plastic and contaminate the water. To extend the shelf life of water stored in transparent containers, place the containers together in dark plastic bags to keep out the light. You can also store water in the freezer. Being frozen keeps water at an acceptable quality for a longer time, and the presence of this ice in the freezer will help keep food from thawing in the event of a power outage. Keep in mind that when you store water by freezing it, you should not fill the container all the way because water expands as it freezes.