Testing un gassed Ph


Community Member
Jan 9, 2023
Dallas ,Tx
Well I’m trying to test my un gassed ph . I removed a water sample from my tank and added and air stone . 24 hrs later I tested my ph in the sample with my Milwaukee meter . I got 6.74 which is high for my norm . Then I turned off air stone and waited 2 hrs and re tested . Now the ph of the sample is at 6.05

Which of the numbers do I trust and why ?

Thank you
That's a little strange. Normally once it's been degassed, it's been degassed. When was your probe last calibrated? Do you have an alternate testing method to test the probe against?
I do I just need to calibrate my new pH tester

I have calibrated this Milwaukee pH probe only about two weeks ago.

Thanks for the details I’ll go ahead and get the alternate pH tester set up was just trying to get it done with what I had set up currently
Ok I calibrated my apera ph 60

Ungassed ph 6.13
Ph after 1 hr lights on 4.86 ( at this point I missed my timing of lights on )

So it appears that letting the aeration settle for a while is important to testing your un gassed pH at least from what I have figured from this little experiment.