Despite 90 degree temperatures outside, out pool just isn't warm enough to enjoy. Its in a shady area and is darn cold.

It is basically two "hot tubs", homemade out of concrete block and PVC pipe. When we bought the house, we decided they were worth trying to get running. With the help of a great friend and pool guy, they are up and running with a few issues to still work on.

So we really don't want to invest much into these pools that may not last.

Heaters: what's cheap? Redneck pool heater is amazing. What about a regular water heater?? Backflow preventer on one end and a pump on the other.

Thoughts?