I would suggest seriously looking at a solar system. I have an above ground pool but they work for in ground as well. I only installed my solar system a few months ago. I did not put much faith in it working too well. Well let me tell you how wrong I was. I am so impressed with its performance I will never be without a solar system again, no matter how big or small a pool I have. If the system is sized properly you will get more heat than you can use.
I installed 2 2x20 sungrabber panels on my south facing roof. The panels are 50 feet from the filter and 14 feet high. I plumbed it in 1 1/2" pvc with a manual bypass kit. After I initially turned everything on and made sure I did not have too much back pressure, about 2-3 pounds, I took the floating thermometer and placed it in the return stream. The water returning to the poll was 2 degrees higher than the water itself. This temp increase was sustained. About 2 hours later I found a few leaks in one panel, damaged. I have only been running 1 panel since, waiting on the warranty replacement. I have had the pool up to 92 degrees after 3 good sunny days. I keep a solar cover on when no one is in the pool to help retain the heat.
Oh, did I mention it costs nothing to run. Can't beat the price of free heat.
I love my solar panels!!!!!!!!!!!!!!!!!1
