Has anyone found a pH probe that actually works and is reliable?

[platon20]

I've bought like 3 units, everytyhing from a cheap $10 proble to a fancy $100 probe and they are all garbage.

You do all the calibration and normal set up and then you start using it for real water samples, and then you get 5 different readings on pH. I'm not talking about 7.5 vs 7.6 either I'm talking 7.5 vs 8.3

Furthermore if the water sits in the test cup the pH dramatically changes. For example it may read 7.5 when you first check it, but if you test again in 2 minutes it reads 8.0

Has anyone found a probe that is reliable/consistent?

 

[TinFoilHat]

You have a test kit for PH so just use it.

 

[PoolBrews]

I use the Apera Instruments AI311 Premium Series PH60 Waterproof pH Pocket Tester Kit. I've been using it for 5 years, and it works fantastic. Very accurate. $79 at Amazon. I typically calibrate it twice a year.

 

[ajw22]

Furthermore if the water sits in the test cup the pH dramatically changes. For example it may read 7.5 when you first check it, but if you test again in 2 minutes it reads 8.0

That is a characteristic of the test sample and not the probe.

Water sitting in a test cup will outgas CO2 and its pH will rise as it sits there until it reaches an equilibrium.

That is why you need to test the sample immediately after taking it from the pool or cap the sample until testing to prevent CO2 outgassing and pH rise.