Do I need a new PH Probe?

[Mikef1]

I am in the process of setting up my PH controller but I havnt used it in about 3 years. It is a Milwaukee unit and when I tested it it seemed ok because I it registered at 8.1 which is about right considering I am cycling the tank right now and the lights are off. To verify this I put the probe into RO/DI water and at first it went up and down but then settled at 8.0. I know the ph is much lower than that! My question is do you guys think I need to just calibrate it again or should I purchase a new probe for it?

 

[Len]

You should be okay calibrating it if your pH probe was stored properly (the probe end kept wet).

RO is hard to take pH of because there is little ions left in the water for the pH to take a reading of. Sometimes RO will read low or high when it should be a bit below 7.

 

[Mikef1]

Len, it wasnt stored properly . It was dry the whole time it was not being used. Should I go ahead and purchase a new probe? I think there about 40 bucks for this unit.

 

[Anonymous]

Len, it wasnt stored properly . It was dry the whole time it was not being used. Should I go ahead and purchase a new probe? I think there about 40 bucks for this unit.

if the probe was kept dry then yes you need to replace it

 

[fungia]

ya, but a new one. i dried one of mine out and when i got a new one, i found out the old one was very inaccurate.

 

[Anonymous]

You may still be able to use it. I would replace the probe if it won't calibrate with the calibration fluids, no matter how I set the slope or intercept.