Question about digital ph monitor

[Phishman1]

I have a PH80 digital. Recently my PH was way off and I almost killed my tank, but thankfully didn't due to ph adjustment. My fault because I did not know you had to calibrate them so often. Basically throwing it in the trash and going back to chemical 3 drops method. Question is this, what do people use who have digital monitors and how often to calibrate? Any on the market that are accurate without calibration so often? Jim

 

[rlederer]

I have the same problem. I have two pH monitors and liquid test kit and get different results on all three. Calibration is difficult as well. I don't know what the answer is. (BTW it's always pH.)