Chlorine Stabilizer Slows Down Chlorine

In Healthy Water by Steve DonohoeLeave a Comment

The SCP (Our Class) Building in San Diego

We opened up our 2010 SCP San Diego CPO class this past Thursday and Friday, March 4-5.  A new boss was in town, too – David Ogren — a.k.a. “David-O”.  Congratulations on the new job and promotion, Dave!  And thank you for the red carpet welcome!

We arrived at SCP the day before class to set up the classroom in advance and everything went very smoothly.

As always, the first day of class is jam-packed with information, but it was no problem for this class!  We had a few 15-20 year veteran pool guys, a 25+ year  aquatics manager of a nearby school district (11 competition pools), and a couple of pool operators/managers of an oceanside resort — one of them was also a bio-chemist!  We had great discussions about pool water chemistry; water balance, chlorine, cyanuric acid (aaah, yes–“cyanuric acid” – “stabilizer” – “conditioner”–whatever you want to call it).

Chlorine / CYA Chart (all values are ppm)

As we were going through CT values of various pathogens it was pointed out that the values did not take in to consideration the effect of cyanuric acid on chlorine.  Yes, CYA does protect chlorine from the sun, but it also slows down the killing time AND oxidation times of the pathogens.  How much does it slow it down? — well — it depends on how much cyanuric acid is in the water.

Here’s a simple chart that shows how much chlorine is needed to have the same killing/oxidation effect per amount of CYA.

Steve Donohoe and David Ogren

There are a couple of great swimming pool maintenance forums out on the internet: Trouble Free Pool and The Pool Forum.  They both have very sound  technical information, backed up by research papers.  This chart comes from the Trouble Free Pool forum: HERE.

Thanks again, David-O….and thanks to your entire SCP crew!  See you again in June!

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