FC by itself isn't enough to say one way or the other; it's how the FC relates to CYA that matters. FC 10 with CYA 20 is at shock level and I wouldn't go in. FC 10 with CYA 90 is the high end of the normal range and is no problem to swim in. Check out the Chlorine/CYA chart to help with this decision.
--paulr
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Welcome to TFP! For a wealth of pool care information please check out our free Pool School. If you are in need of specific help then we encourage you to Register and ask us here in the forum!