Seriously contemplating installing a ground-based solar heater this season. Have read a lot of the posts here to get ideas. Am thinking about four 4x20 Fafco Solar Bears, laid on black weed cloth on the ground, with a Goldline controller. As our pool is about 720 sf (freeform), this will be a bit under 50% coverage... I don't know if output will be sufficient, but am hoping for maybe 5 deg. increase and/or less need for the solar cover.
I've attached a (cheesy) plumbing diagram here, and am interested in any feedback on design, as well as any performance comments... On the plumbing, the bold lines would be either supply or return, and the light lines would be the opposite.
As we have a slight slope toward the pump, I'm wondering if I would need some sort of vacuum breaker on each one to allow drainback. I am intending to leave them connected year-round (though drained along with the pump & filter in winter). They may require blowing out for winter, as I don't know if the slope will be enough for full drainback.
Thanks for any advice / help!