How do you know what persentage to run your pool chlorinator? Why not run it at 100%?

You know how long or what percent to run it by testing your FC and adjusting the percentage and/or the run time.

You could run it at 100% but you're usually better off balancing run time and percentage to get the right amount of FC being generated.

There's a post in Pool School about setting your %.

I've been running mine at 50% this past month due to the hot weather we've been having. Usually I get by with it at 40%.