Free chlorine high


Gold Supporter
Bronze Supporter
Jun 11, 2018
Verona, MO
It depends...
CYA level? What time was tests performed? How much longer will pump/swg run after test? Folks in pool after tests? How consistently has the FC been in this range?

If CYA is 80, target is 6 FC so you are a bit high. If taken in AM, UV will work on it some. If several get in the pool after the test, you will lose a bit more.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

If your CYA is 80, then an FC level of 8.5 is just not an issue. It is always better to be on the high side than let the FC get too low.

Keep in mind your "target" is 6, but any level up to 31 is OK to swim in.. In theory, you want your FC to be 6 or above all the times.. If you quit producing chlorine at midnight and start again at noon, you want your FC to be 6 when you start producing chlorine again. Just pretend that the pool will explode if your FC ever drops below the minimum level of 4 ppm.. It won't of course, but the idea is you want to be at your target and not get anywhere close to the minimum.


Jim R.