Finally got the our 27' ft ag round installed last Monday. Swam on Sat with 82 degree water. Now what sun screen is effective . And will NOT stain the liner in a couple of years. Used Coppertone Sport (SPF 50 and waterproof) and all of us (4) got burned. Some more that others. My four year old got it the least because he was on the steps 90 percent of the time and not really in the water. I look like a lobster on my chest and back.