Searching for more about "Operating Swiming Pools at High PH"...

[waterbear]

As Ben said, when that post was written the relationship between TA and pH was not as fully understood. Main cause of pH rise in pools (when there is no curing plaster) is outgassing of CO2. Your pool is carbonated much like a bottle of soda. That carbonation comes from the TA (bicarbonate) in the water. The higher the TA the higher the higher the carbonation. The higher the carbonation the faster the outgassing of CO2. The faster the outgassing of CO2 the faster the rise of pH to 8.2 to 8.4. If the TA is lower an equilibrium is reached with atmospheric CO2 at a lower point and the pH tends to stay lower.

If you are interested in some of the chemisry behind this then this post will explain it.

FWIW, I run my own pool between 7.8-8.0 (partly because I have 50 ppm borate and the secondary boric acid/borate pH buffer acts in the opposite direction of the carbonic acid/bicarbonate buffer we call TA and keep the pH in that range for an extended period of time.

The "dial" in your Taylor kit is the Watergram and it is a device for computering the Langelier Saturation index, which is one of the calcium saturation indices used for pools. It really is not useful for a vinyl pool. and is often wrongly applied to other surface pools. It can be used to predict scaling conditions BUT the main factor in the mathematical equation behing it is pH SO (drumroll please) HIGH Ph IS THE MAIN FACTOR IN ANY POOL THAT PREDICTS SCALING CONDITONS!. As far as aggresive water conditions, the Langelier Saturation index CANNOT predict whether water will be corrosive to metals at all. It can predict whether water can be aggressive to a plaster finished pool but, once again, the MAIN faster here would be LOW pH (which is usually only a problem on pool runs on either trichlor or dichlor).

In other words, you can play with it but it means nothing to your vinyl pool. Your pH is what is important and your TA is what determines how fast your pH will rise.

Also, a few fun facts about high pH pools. Like I said, it was developed by United Chemical several years bck and they sell a whole line of bromine based pool additives that require a high pool pH AND 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!