[Bluebasil]

Hi, I tried again raising ph (was trying to raise pH to 9.5) with NaOH and something similar happened. I would raise pH, get reading with pH meter, then next day I would come back, measure again and I would get a different reading. Didn’t know what to make of it, so I used pH strips just to see what reading I would get. The strips coincided with the reading that I would get after some time had passed.
I am thinking that what was happening is that my pH meter wasnt giving me a correct reading because it was calibrated with 4.01 and 7.01 solutions. Never with a 10.1 solution. So when I tried to measure a higher pH than 7, it wasn’t giving me a correct reading. That is the only thing I can think of. Either way, I am getting a new pH meter, and calibrating with 4, 7, & 10 and Im hoping that will solve the issue.
I will report back if I see something different.

[Bluebasil]

Thank you for the suggestion. I will try.