PH testing question

[Plumber1]

Hello, I have been second guessing my PH test lately, after 10-15 seconds my ph reads 7.4 but when i let it sit for a minute or so while i do another test it drifts up to 7.8-8.0. Could someone please confirm when to read the test or is something wrong? I am testing with a tf-100 kit. Thanks Scott

fc-5.5
cc-0
ph-7.4?
ta-120
ch-30
cya-30+

18x34 ag, 14000 gal.

 

[reebok]

put the drops in, cap it, invert a few times and read it.

 

[PaulR]

One of the chem/test gurus may have a detailed chemical-process answer, but for pH you read it right away.
--paulr

 

[Guest]

Add the reagent to the sample, cap , invert 3-4 times to mix (don't shake), and read. If you are going to do demand tests do them immediately after the pH test.
pH can drift up on sitting, particularly if your TA is high.

 

[Plumber1]

Thank you, Scott