Prob replacement?

[jjdezek]

I have a PH probe and salinity probe that I've had for over a year at least. I was wondering how long there good for, do they need to be replaced after a certain amount of time? I tried calibrating the PH probe but it still doesn't seem to be reading right. Haven't messed with salinity probe but it's reading low also.

[lnevo]

Ph probes don't last forever. I've seen 6months to 2 years. I've seen much better duration with the lab grade ones.