IDEAL Chlorine levels & testing


Well-known member
May 28, 2010
I need help understanding something.

The local Pool Supply store tells me the ideal chlorine TC level is 2 to 4 ppm and the FC is also 2 to 4 ppm and the CC is 0.

My 'Aqua Check' test strips say 1 to 5 ppm FC.

The Pool Calculator says 7 to 12.

My Taylor test kit only lets me test FC and CC (No TC)

So I'm a little confused. First, Why is the Pool Calculator 'Goal' so much higher than everyone elses?

My Taylor test kit gives me the following readings: FC = 9.5 and CC = .5

I have no idea what's going on with my chlorine. Can someone help me understand? Also, Why doesn't the Taylor kit offer a TC test? And... Is my CC of .5 something to be concerned about?

Thanks in advance



TFP Expert
LifeTime Supporter
Feb 23, 2008
Denton, TX
Your TC is the sum of your FC and your CC. So you add the two together and that gives your your TC.

The only way to know what the proper FC is for any pool is to by knowing what the CYA in the pool is. See the Chlorine CYA Chart to note this relationship. Any other ranges given to you by a pool store or other source are completely arbitrary and have no basis in science. CYA level always dictates the FC level.

Any CC > 0.5 ppm should be addressed by shocking. If it is 0.5 or less than that, nothing special aside from maintaining a proper FC level needs to be done.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Also, Why doesn't the Taylor kit offer a TC test? And... Is my CC of .5 something to be concerned about?
If you add FC and CC, the result is TC. The .5ppm CC is well within acceptable limits.

Pool stores and test strips are what causes most folks to get into problems with their pools. Whats taught on this forum is a superior, more accurate way of managing your pool. Believe you're own testing (it's the best).


TFP Expert
LifeTime Supporter
Nov 5, 2008
The pool store is correct assuming your CYA is 30, but in the real world of pools managed by pool store advice, a CYA of 30 is pretty rare.

The test strips tell you that "Ideal" CYA is 30-50, and in that range we say your FC ought to be be 2 - 6. But the test strips then tell you that CYA is not "High" until it is in the 150-300 range. And this implies that at any CYA up to 150 you are fine with FC of 2 - 6.

They both ignore the effect of higher CYA on what portion of the FC is truly ACTIVE and what portion is held IN RESERVE by the CYA.

Strips would be much too complicated were this relationship acknowledged, and the lack of precision from the wide value ranges indicated would become apparent to all strip users. For the pool owner who wants it all to be easy, one step, testing this would be a problem.

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