I'm still fairly new to the site but I can't seem to find the answer to safe chlorine levels. I understand the recommended levels and how certain factors require more FC for balance. But I've also read that one should avoid swimming in levels above certain thresholds. When I look at the recommended shock levels, and the direction to maintain them, I want to know when it is OK to swim. Am I misunderstanding the directions or have I been basing my assumptions on a myth?