Vacation Strategy

Quote:

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Originally Posted by KurtV

I'm still a bit confused as to what the HOCl (ppm Cl2) label at the top of the chart means.

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The "HOCl (ppm Cl2)" is the concentration of hypochlorous acid, what I've been calling "disinfecting chlorine", and the "ppm Cl2" just says that all chlorine measurements are measured in part-per-million as weight of chlorine gas (that's just the convention).

With no CYA and at a pH of 7.5, the Free Chlorine (FC) concentration is double the disinfecting chlorine (hypochlorous acid) concentration because the FC (with no CYA) measures both the hypochlorous acid (HOCl) and the hypochlorite ion (OCl-) and these are roughly equal in concentration at a pH of 7.5. So that's why I doubled the disinfecting chlorine (hypochlorous acid) concentration to get the FC level when there was no CYA.

Richard

Got it; thanks.

Well I am back from a wonderful 10 day vacation. I had somebody add 1.4 gal of 6% bleach Sun/Tues/Thurs. I do not use a pool cover. I turned off the heater.

I left on a Friday morning with the following numbers..

FC = 10
CC = 0
pH = 7.4 - 7.6
TA = 100
CYA = 30
Temp = 86

Returned on the following Saturday night to a perfectly clear pool...sparking actually

FC = 8
CC = 0
pH = 7.8 to 8.0
CYA = 30
Temp = 105 the temp was set at 110!!

Fortunately the person adding bleach noticed the pool was getting low and added some water.

We are still in the investigating stages...but have a few leads...

Sounds like your strategy was a success! Congratulations!