Installing and running Natural Gas or Electricity to heat a pool is EXPENSIVE!!!! Save a ton of money by building your own Solar Pool Heater. This is just one of many examples out there, but I was able to accomplish mine for roughly 80.00 without a cover and not including the pump. I can maintain my pool at roughly 83-86 degrees with this exchanger and a pool cover at night to keep the heat in. With a clear cover over the exchanger, I'm sure that temp will get higher!! The coil can be a bit tedious, but over all this an easy project that just takes some time and basic materials.
Look for part two at GDB channel to see the end results!!! Get out there, save that money, and enjoy a non freezing pool!!!