Quote Originally Posted by waterbear View Post
As Ben said, when that post was written the relationship between TA and pH was not as fully understood.
Just so.

I had discovered, as a result installing an ORP-pH controller on some spas at the Hyatt in Atlanta that aeration + pH control would eliminate carbonate alkalinity in 15 minutes. I repeated the process 3x, because it violated everything I'd been taught, and I was still 'drinking the pool industry's kool-ade' at that point. (I'd just become a CPO instructor the year before, and hadn't yet found all the errors in the CPO exams!)


when it was being recommended most people were trying to force the pH down to about 7.2 or 7.4 and did not understand the roll that TA plays in pH. The misconception (still taught by many in the industry even today) is that higher TA will stabilize pH. Nothing is further from the truth and people found themselves battling high pH and even trying to raise their TA to combat the high pH when in reality they were making the situation worse!
And, I'd also discovered that many of the problems reported when people tried to run commercial pools on bleach disappeared when you let the pH drift up to 7.8 - 7.9. It was this, and some related experiences, that led me to began to understand that many of the difficulties people had with pools were artificially generated by the pool industry's focus on a set of arbitrary numbers.

I didn't yet know how pH related to the HOCl/-OCl chlorine curves published everywhere,

(from Santa Barbara Controls, an ORP/pH controller mfg)

but I knew that it once you added CYA, it wasn't what was being shown. Now, of course, Richard (Chem_Geek) has used Wojotowicz's and prior work to create this one:




When I was looking for an example chart to link, I found this unintentionally funny post on poolspaforum:
http://www.poolspaforum.com/forum/in...howtopic=19260
where someone in the pool industry offers to help Chem_Geek to take some of the industry training classes, so he could understand that standard, and very wrong, curve better. What's funny is that, by the time of that post (2009), Chem_Geek knew more about overall analytical pool chemistry than anyone I've every known in the pool business. There were (and probably still are) some PhD chemists in the biz, but all the ones I've talked to are so lost in the 'trees' that they don't even KNOW that there is a 'forest', so they know more of some of the details than Richard does, but still don't understand pool chemistry as a whole.