On TFP and PoolForum

[chem geek]

Though BBB may not have fully originated with Ben, I think he was one of the first to recognize and attempt to quantify the relationship between chlorine and CYA in terms of chlorine's effectiveness against algae prevention (notwithstanding the flawed methodology in the Sommerfeld/Adamson paper). A combination of experience and I believe some conversations with chemists culminated in Ben's Best Guess CYA chart. Though the science behind this equilibrium relationship was definitively determined in 1973 and presented at a symposium in 1974 published in the following reference

J. O'Brien, J. Morris and J. Butler, “Equilibria in Aqueous Solutions of Chlorinated Isocyanurate”, Chapter 14 in A. Rubin, ed., Chemistry of Water Supply, Treatment and Distribution, 1973 Symposium, (published 1974), Ann Arbor Science, Ann Arbor, MI, pp. 333-358.

this only implied a fairly linear relationship (when the CYA ppm >> FC ppm) whereby the ratio of FC to CYA roughly determined chlorine's effectiveness (that is, the hypochlorous acid concentration). As for what ratio inhibited algae prevention, this apparently came from Ben's experience with many pools over many years.

For this, and of course for PoolSolutions with all of the other tips and useful information and for The Pool Forum itself, Ben deserves a lot of credit.

At the time I ran into The Pool Forum, I had already begun working on my spreadsheet determining a Calcite Saturation Index since the LSI in the industry didn't match the Taylor watergram and seemed wrong in some of its terms. I then wanted to add the chemical equations for the chlorinated cyanurates (chlorine combined with CYA) when I ran into this website and started conversing with Ben. I eventually found another source for the equilibrium constants, but made The Pool Forum my home for posting results (suitably relegated to The China Shop due to its technical content).

I am currently trying to shift the pool industry into adopting these chemical principles into standards such as the APSP-11 and into training such as NSPF CPO and APSP Tech courses. I also want to initiate a study on using a small amount of CYA in indoor pools to reduce the over-chlorination in such pools including the possible greater production of disinfection by-products (indoor pools without CYA have 10-30 times the hypochlorous acid level of typical outdoor pools with CYA). Another study I would like to see is on using sodium chlorite as a way of generating chlorine dioxide (which inactivates Crypto at least 15 times faster than chlorine) in commercial/public pools after a diarrhea fecal accident since the CDC now has guidelines that would effectively eliminate CYA since it would prevent fighting against Crypto (see here) . This will be a long haul, but I believe it to be worthwhile.

Were it not for Ben and The Pool Forum, I doubt that I would have pursued these efforts as I would not have known that the problems I encountered with my pool after 1-1/2 years (with CYA getting to 150 ppm) were so common and so easily mitigated.

Richard