Most of us do not drink enough water. To figure your daily water goal, take your body weight and divide it by 2, this is the minimum number of ounces of water you need to drink per day. So if weigh 180#, you need to drink 90 ounces of water per day. Start here and try to work up to 1 gallon per day. FYI, There are 128 ounces in a gallon.