I am now in charge of our pool. Will have many more questions; such as:


Well-known member
Jul 16, 2019
1) if CC is > .05 pool school reads to “SLAM”. Won’t that put FC out of balance to CYA?
2) Under Daily Pool Care Schedule it states, Test Chlorine Level. Which one, FC, TC, CC?


Gold Supporter
Silver Supporter
TFP Guide
Mar 25, 2018
Chandler Arizona
CC at .5 is nothing during this time of year. With the sun being off axis, it’s affect on CC is diminished. As Marty suggested, do an OCLT to quickly determine if something is living in your water. Otherwise, no worries. :cheers:
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Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
TC is one of the test in the K-1000 kit that was included in the TF-100. Should I not use that one?
The only use for the OTO test is to see if there is chlorine in the pool water. Such as if you test an unexpected 0 FC with FAS-DPD. Check with the OTO to see if you made a mistake.
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TFP Expert
Mar 2, 2011
Most CC is transitory. You can usually resolve it with a slightly boosted fc/cya of about 15% and some sunlight.

A pool cover can sometimes lead to CC buildup, but usually nothing to worry about.

Periodically, do an OCLT to detect any excessive fc loss due to organics etc.


Mod Squad
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
My pool will register 0.5 CC if my cover has been on. Open it up and voila! A couple hours later its 0.

Its just a matter of getting confident with the variables. I know how the cover restricts sun exposure burning off gasses. If I felt it was possibly actual contaminates, I might do an OCLT.

Bottom line is don't panic! Some pools and spas will *never* be less than 0.5ppm, yet never more either.

Maddie :flower:
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