Aloha, everyone. I found it hard to get the solar 20' heater off ebay shipped to Hawaii at a reasonable price, so I decided to fashion one of my own. Here it is.
1: 500' of the irrigation black pipe from home depot
2: It is coiled on the top of a 8'x20' container starting along the outside edge. Coil is held in place by "fingers" that are vertical, so the tubes are space 1/2 apart
3: Water comes from my return line of my filter pump and amount of water is adjusted/diverted to the coil by a valve. (but all the tube from the discharge line of the 1 1/2" pump to pool is tee'd off to the 1/2" x500' coil.
4: I can regulate the temp of the water coming back by the 1 1/2" valve.
How hot should I want the water coming back? It will vary according to how much water I am diverting and of course the weather. I am doing 20 degrees above pool temp and the water is flowing at about the volume of a 1/3 open water faucet, about 2 GPM.
I thought I would be getting more heat out of it. Am I expecting too much. (I can add another 500' x 2 lengths if needed