Is a digital pH meter accurate at high chlorine levels?

[farsonic]

Hi there,

I've read that pH measurements are inaccurate when shocking a pool. Is this statement for my Taylor test kit only or does this also cover a calibrated digital pH meter?

Cheers

F

 

[JoyfulNoise]

This is only true for the phenol red color matching reagent. A good quality pH meter should not be affected by it. However I would rinse the probe off in distilled or dechlorinated water before storing it.

 

[needsajet]

Thanks for asking cause I was wondering about that as well. It's great to have the answer from Matt.

It's worth mentioning that the large addition of chlorinating liquid at the beginning of a SLAM will raise pH, but you don't need to correct pH during the SLAM. Before the SLAM, pH is adjusted to 7.2 to 7.5 to allow for this. As the chlorine is consumed, the pH will drop back down, so the overall effect on pH is negligible.