At 204, 4 liters is probably about right - maybe even not enough if the soda you're drinking is caffeinated, you drink tea, and you work out or your job involves physical labour. If you don't like Gatorade, you might try the packs of 'Emergen-C' powder. It can be mixed into your other drinks, comes in different flavors, and also has different formulations containing additional supplements (i.e. glucosamine/chondroitin).