TCB,

The Fafco panels are very good, but be aware that oversizing your panels (or using a cover) is really required to get the temps you want.

We have a similar pool to yours and started out with 4 4x10 panels and ended up going with 4 more (for a total of 8, natch :>). In a similar climate (central Florida) we can easily get the pool water in the 90's with only a day or so of sun (indeed we've lately been struggling with using the solar to cool the pool down at night, since I don't like the water warmer than 88 and if I start with water at 85 in the morning the sun will heat it to 90 by the end of the day).

If you don't want (or can't have) that many panels then you'll need to use a cover. I think they are a PITA and refuse to have them, but you'll save at least 2 or 3 degrees right now by using one.

Cloudy days will definitely cool a hot pool like you want down quickly -- we had 92 degree water that dropped (even with the panels) to 83 in about three cloudy days. However, today we had about 3 hours of sun and I was quickly able to get the pool back to 87 (I probably could have gotten it to 89 if I had wanted it warmer).

So -- to summarize, make sure you have enough panels (or use a cover), and understand that you will lose temp quickly during cloudy spells.