calibrating my ph probe


New member
i got a replacement probe which was working great and then i tried to calibrate it the other night because i was getting strange and jumpy readings all of a sudden and it said the probe was defective. what am i doing wrong here? the probe stays in my sump and has been working flawlessly for a month and now this.


.Registered Member
What controller? If an AC3Pro are you putting the temperature probe in with the pH probe during calibration? The temperature probe is a ground reference for the pH and ORP probes on the 3 Pro.