Big time daily chlorine loss

Ronald U.

Bronze Supporter
Greetings. I have always noticed a large daily drop in FC during the summer. Up to 5 points is not uncommon for my pool. However, it seems to be even more lately. I target FC at 7.0 every morning. This morning's reading, pre-chlorine addition, was 0.5 points. 6.5 point loss during the day? Wow. Can anyone explain this? Does anyone else see this level of loss? True, I am in SE Texas, pool has direct sun about 9+ hours right now. Is there a solar cover that could cut down on my liquid chlorine usage? Thank you as always. I trust everyone is enjoying their pool.


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Add 10 ppm CYA via the sock method. Test your CYA 24 hours or more after it is all dissolved.

I suspect your CYA has fallen some due to high water temperatures.

Get your FC up into target range ASAP.
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