I remember hearing that generally Free Chlorine levels can be much higher than the pool stores will recommend.
I was having a problem getting my FC to hold. Last night, I finally decided to do a good shocking. I used 3 gallons of 10% bleach.
By morning my FC was holding at 11ppm. Later that day my wife had a friend and her two young boys, aged 4 and 2 over and they swam for about a half hour.
When I got home, I checked the FC and it was still 9.5 and that was after a good rain shower. I figured the boys must have been swimming in 10PPM FC before it rained.
The good news is that the free chlorine is holding. Is there any health risks swimming in it or getting a mouthful of 10ppm chlorinated water?