Quote Originally Posted by Xndman
In regard to the speed through the panels, I would have thought that the water flowing through the panels more quickly would have less time to "heat-up" from the panels. Also, I do have my panels on the ground. I assume they'll work better if I get them off the ground.

Thanks!!
Maximizing heat transfer is key for a solar panel. According to thermodynamics, heat transfer is proportional to the temperature differential between surfaces or materials. Therefore, the higher the temperature difference between the water and the panel, the higher the rate of transfer (BTUs/hr) will be.

Another way to think of it is that if the water is moving too slowly in the panel, it will heat up to the panel temperature before leaving the panel. At this point it is not transfering any more heat to the water. Ideally, you want the water to leave the panel only slightly warmer than entering so that heat is continually transfered to the water at the highest rate. This why when the panel is 10 degrees warmer than the pool water, raising the pool temperature the first 5 degreees is much quicker than the last 5 degrees.

Having said all that, higher flow is only better for heat transfer. To lower your electric bill, you may still want to run at low speed. Even though the heat transfer is less, it may still be more than enough.

Also, too much flow can be damage a panel as well but that is usually at pressures exceeding 25 psi.