I don't I'd swim above FC 20.
Here's a link for another site chlorine level chart that I like. http://www.poolsolutions.com/gd/best-guess-swimming-pool-chlorine-chart.html Scroll down for the pretty color chart.
Hope it works for you.
Here's a link for another site chlorine level chart that I like. http://www.poolsolutions.com/gd/best-guess-swimming-pool-chlorine-chart.html Scroll down for the pretty color chart.
Hope it works for you.