As we all know water is cold coming out of the ground or even from underground piping in cities. The hot water heater has to work hard to heat the water up from say 50 degree or cooler to 95 degree or hotter. During the summer months hot water heaters, dryers, stoves and air conditioners are the biggest power users. How I came up with this idea of a way to save on hot water cost came from what I did when we lived in Spokane, Washington. We had a 4' x 30' above ground swimming pool, being in the Northwest the water never seem to get warm enough so I built a solar water heater out of a 4' x 8' plywood and hot water PVC pipe covered with clear plastic and heated the pool water. Using this I could easy get the water way to hot for swimming, matter of fact the water coming directly out of the solar heater piping was so hot that It would burn my hands. Now lets get to the project I have planned. Since the water coming directly from my pump to the hot water heater is cold I started thinking about heating the water up before it enters the hot water heater cutting down on the time the heater would stay on which would save energy therefore money. In the southern part of the States the hot water heater might not have to come on at all, but I also know that this would work in the Northern parts because of the project I did in Spokane. I will need two discarded 30 gallon hot water heater tanks which I should find at no cost or cost very little because people have an element go bad in a tank they will just go buy a new one and throw the old one out behind the house in the trash pile. Second I will need a few bags of cement to pour a slab big enough to lay the two tanks onto. Then I will need a 4' x 8' sheet of rough plywood and a couple of 2" x 4". Enough hot water type PVC for running from the water pump line to tanks also to connect the two tanks together and from the tanks to the inlet piping going into the hot water heater. Instead of using plastic like I did in Spokane, I will use a glass pane to cover the box that I built to hold the tanks. Will need flat black paint for the tanks and the cement slab, I will insulate the wood sides of the box. I will have to make sure I place the tanks in a position to get the most sunlight possible during daylight hours. As said I have not tried this project out yet but will be building it this winter for next summer but I'm sure that it will save me quite a lot of money that I have been paying for hot water. If anyone has already done this or has a better way I would like to hear from you so please comment.