[71T Targa]

Here's my take on solar pool heaters, and yes, I've had them.

1) When the sun is out they work great!
2) You don't really need/want your pool heated when the sun's out.
3) When it's cloudy they don't work, and can actually lower the temp of the pool.
4) You really need/want your pool heated on cloudy days.
5) If you accidentally leave them 'on' during the night, they can greatly lower your pool temp.