Quote Originally Posted by CarlD
I have a 16x40 pool, 20k, 640 sq ft and the equiv of 3 4x20 panels--240 sq ft. Yesterday, in North-Central NJ, the water hit 92 deg. I frequently run only half the system.

My parents had a 13,500 18x33 oval (525sq ft), with only 6 hours sun a day on the pool and on the 4x20 and 4x10 panels (120 sq ft) I installed and they went from 78 deg (brr) to 84 deg all summer--just six hours a day. Total cost: Less than $500, inclding a 4-way valve for the DE filter's output, TigerFlex, fittings and the panels.

I think 2 to 3 4x20 panels will do you VERY nicely.

Not to doubt the effectiveness of your system, but that does not sound like much heat generation. I have a 20x40 IG and use a heatpump and solar cover. I had heated the pool up to 79 degrees with the heatpump. I am in NorthWestern NJ and my water is 85 degrees just from the outside temperature and the sun hitting the pool and being covered at night with no other heat added to the pool. In other words, just by having the solar cover on it it has gone up 6 degrees in the last week.