One gallon(4liters) per person per day is a minimum. I started small by washng out 2 L pop bottles and filling and adding 4 drops of bleach per liter. I refill every six months. At first I did this June 1 and Dec1 but as the amout I had stored went up I've started doing some every month to make it easier. I now use container up to and including the Reliance7 gallon containers. I've have decided for me the Reliance 2.5 gal containers are the way to go. They are easy to move and fill. While the 7 gal are nice having recently had a heart attack lifting 60 lbs isn't my idea of fun. I consider 1 2.5 gal containers to be a one day supply. If you can afford them the military water cans from Brigadequartermaster are the best going.

Bob