Determining if a pH probe needs to be replaced

[WarDog]

I had my pH fluctuate from 7.8 to 8.4 sometimes throughout a day. If you're really concerned, get some calibration fluid and re-calibrate.

[byee]

Warren,

Thanks for the quick response!

I just replaced my pH probe and calibrated on Tuesday. The pH peaked at 8.43 with a low of 8.33.

Would you know what the typical pH swing should be?

I just set TEMP COMP = ON for my Apex. Perhaps this will provide me with a more stable reading.