How time-sensitive is out-of-range pH?

[Newdude]

Waves are waves. Whether it's surface movement or a bazillion little shakes of the sample container.

That's not to say it has to be different when it gets to the store, but there's no guarantee it's not compromised.

You can also skew it by letting the sample warm up first. For example, it sits on the counter for an hour and then warms up further in the car. You're getting a good reading of the sample, but the pool is X.X and the sample may be X.Y or Y.Y. if it's orange or purple it's easy to see. People split hairs on what shade of pink it is when 7.4 to 7.6 doesn't change the price of beer. Maybe it was 7.5 and both are close enough.

 

[pjt]

pH: 7.1 (estimate based on slightly below the 7.2, but well above the 6.8 indicators)
TA: 60

That's good. No need for baking soda. The pH will rise by itself. Aerate to speed up the process if desired.

 

[Mdragger88]

Speaking of warming up the sample - you should do so for your cya sample next time you’re testing it. That test is best done at room temp or above or the results can be a little off. You can just stick the little sample squirty bottle in your pocket a bit before proceeding with that test.