If live in a climate where installing a screened enclosure over the pool is possible, this works extremely well for controlling pool heat in the summer. Screen knocks down UV rays by over 50%. Here in central Florida, my pool never gets above 90 in the summer due to my screened enclosure. The neighborhood pools that aren't covered hit high 90's during this same time.
My pool in GA was similar - I couldn't have a screened enclosure because they still get ice and snow which would have collapsed the screen. My pool there regularly hit temps in the high 90's. I installed sun shades over the pool, and that dropped the temp significantly - into the low 90's. 91 or 91 feels pretty good when temp is over 100 out.