Bottled water should be stored in a cool, dark place. The ideal temperature is between 40 and 70 degrees. Direct sunlight and fluorescent light can cause the water to turn green, so keeping it out of these rays is best. You can purchase a cooler cover if you do not have a cool, dark place to store your water. This will help to protect the water from the elements and keep it fresh. In addition, you should rotate the bottles so that the oldest ones are used first.