Translate to:

The Future for pH and Chlorine Standards

  • Rating: No Rating

It appears that the pool industry’s long-time recommended parameters for chlorine and pH levels will be changing in the near future.

The current range of 1 to 4 ppm for chlorine will likely be raised when pool water contains cyanuric acid (CYA), and the pH range will be broadened beyond the current limited range of 7.2 to 7.8. The reason for this change is due to a new understanding of the science of stabilized pool water.

Some years ago, Richard Falk (known as Chemgeek on pool forums) wrote about the relationship between CYA, Chlorine, and pH, and communicated that information to the Council for the Model Aquatic Health Code (CMAHC) that adopts standards for public and commercial pools. As a result, two years ago the CMAHC formed an Ad-Hoc committee with Ph.D. chemists, micro biologists, and other knowledgeable industry members to study that topic.

At the recent World Aquatic Health Conference in October, Richard Falk, representing the CMAHC Ad-Hoc committee, presented scientific data regarding the benefits of CYA and on the chlorine/CYA/pH equilibrium relationships, including bacterial kill rates, and other factors affecting pool sanitizing by chlorine when CYA is present.

To summarize, the CMAHC is tentatively suggesting higher minimum amounts of Free Chlorine should be maintain and proportionately based on the amount of CYA present in pool water. For example, at 40 ppm of CYA, the minimum Free Chlorine level should be at least 2 ppm, and at a CYA level of 90 ppm, the minimum chlorine level should be 4.5 ppm.

It should be noted that the CMAHC is aware of the EPA’s chlorine regulation minimum of 1 ppm and maximum of 4 ppm. However, the CMAHC believes that higher Free Chlorine levels are necessary to achieve safer and healthier pool water. Also mentioned was that a higher pH (above 7.8) does not significantly affect chlorine efficacy (killing power) when CYA is present.

It was clear from statements made by various CMAHC and CDC representatives that standards should be adjusted or changed as science becomes better understood. They also emphasized that flexibility in standards are needed (when scientifically supported) to allow more effective water maintenance.

At some point, the CMAHC and CDC will probably present this science to the EPA in hopes that higher chlorine levels will be adopted when CYA is present. And a broader pH range (due to applicable science) may be forthcoming also.
For more information and a simplified explanation of the science regarding Chlorine/pH Efficacy when CYA is present in pool water, see this link: http://www.poolhelp.com/home/onbalance-research/onbalance-research/...

Dr. Stan Pickens (Ph.D. and water chemistry consultant) has also written a very detailed and scientific paper on “Relative Effects of Chlorine and pH on Disinfection” which will also be available to read.

Views: 10

Comment

You need to be a member of Pool Genius Network to add comments!

Join Pool Genius Network

Comment by Kim Skinner 7 hours ago

Thank you John.

Yes, we owe Richard a thanks. This will be a good step upward and is needed for our industry. I hope there isn't too much of a resistance from the big companies to changing these parameters. But the science is the science.      

    

Comment by John 21 hours ago

Thanks for the update Kim, well done to Richard for pursuing this over the years and to keep pushing for a better understanding. One small step for a man, one giant leap for the industry!

Sign in

E-mail

Password
 or Sign Up
By signing in, you agree to the amended Terms of Service and Privacy Policy.
Forgotten your password?

Events

Latest Activity

Kim Skinner commented on Kim Skinner's blog post The Future for pH and Chlorine Standards
"Thank you John. Yes, we owe Richard a thanks. This will be a good step upward and is needed for our…"
7 hours ago
John commented on Kim Skinner's blog post The Future for pH and Chlorine Standards
"Thanks for the update Kim, well done to Richard for pursuing this over the years and to keep…"
21 hours ago
Diego B. Moore is now a member of Pool Genius Network
yesterday
Kevin Woodhurst updated their profile
yesterday
Profile IconMatt Hancock, Hilde Verbeke and Melanie Brzozowski joined Pool Genius Network
Dec 7
Melanie Brzozowski updated their profile photo
Dec 6
Kim Skinner posted blog posts
Dec 6
Dan Lenz joined Brian Galella's group
Dec 6

© 2017   Created by PGN Admin.   Powered by

Badges  |  Report an Issue  |  Terms of Service

Offline

Live Video