Testing higher pH values...

[AprilsZoo]

...the phenol red test kit doesn't test above 8.2 and at 8.2 you can't tell if you're actually higher. If you were going to operate at a higher pH than the test kit can read, you'd need another method of reading pH such as an electronic meter (a more expensive better one)[...] so obviously this gets more complicated.

The quote was taken from this discussion about the parameters that are relevant to calculating CSI (and other tangential ideas ).

I've noticed in all my time reading and lurking, that the only option ever suggested to those who want to let their pool operate at a higher pH (@ or around 8.2, although some Taylor OTO/pH comparator blocks only go to 8.0) is an expensive, hard-to-maintain electronic meter, in order get an accurate pH reading.

However, there are several Taylor pH test kits that are designed to test a higher or wider range (the following belong to their "slide comparator" series-- which seem like they could be easier to color match with):

• K-1011-K, cresol red, (7.2-8.8)
• K-1011-L, metacresol purple, (7.6-9.2)
• K-1011-M, thymol blue, (8.0-9.6)
• K-1011-U, pH, Long Range, (3.0-11.0) [no reagent specified]

These kits aren't cheap, in the neighborhood of $100+. Probably still less than the electronic meter, which has fragile sensors, and requires calibration on an ongoing basis.

I've seen other Taylor kits, too... but didn't do an exhaustive search to get the kit #'s. No doubt, LaMotte has comparable offerings, as well.

My intent isn't to re-hash the reasons for running pH higher in the first place... I was just trying to figure out why an inherently finicky e-meter would be better than a test kit that is similar to what we are all already used to using.

Thanks to whoever is willing to indulge my curiosity... The monsoon storms have kept me out of the pool and I'm bored, I guess.

 

[chem geek]

This is true. One could get an expensive higher range pH Taylor test kit. That would be a better choice than an electronic meter if one intended to maintain a high pH pool. The main risk for doing that is metal staining, assuming the CH and TA are low enough to prevent calcium carbonate scale.

 

[AprilsZoo]

Fortunately, I don't have to worry about metals, or even CSI for that matter. And since I dropped my TA to 60-70, my pH has been steady as a rock @ 7.5, even when the SWG was working.

I just figured if it was me, I'd rather spend the money on a type of test that I was already used to, than even more money on a persnickety e-meter, that with my luck, probably wouldn't work right most of the time anyway.

So I was curious why I never saw that being recommended as opposed to the electronic meter.

Thanks for the quick reply, Richard.