Malfunctioning pH Probe

[CheifReeferNB]

I have been struggling to get my Neptune pH probes to work on my system. The pH will randomly drift from a reasonable number to 12.2 over the span of 3-12 hours. I will unplug the probe and the display will continue to read in the low 12s.

I initially thought it was a faulty probe so I replaced it with a new one but the same thing happened. I tested the probe isolated from the aquarium in a small cup of tank water with no success.

Neptune systems has not been helpful basically saying they’ve never seen something like this before and it must be a setup issue.

Has anyone experienced this and can help identify what may be wrong?

Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

I tested the probe isolated from the aquarium in a small cup of tank water with no success.

Meaning it still drifted in the cup with nothing else in the cup?

 

[Randy Holmes-Farley Verified Community Expert]

Sometimes, pH electrode readings are messed up by having the wires near other wires or electrical equipment.

Try separating wires if that might be an issue.

 

[CheifReeferNB]

I tested the probe isolated from the aquarium in a small cup of tank water with no success.

Meaning it still drifted in the cup with nothing else in the cup?

Yes. Went in around 8.1 and was at 12 within a few hours.

 

[Randy Holmes-Farley Verified Community Expert]

Sounds like a device (not probe) issue to me.

 

[commod0re]

when I was experiencing issues like this with my Atlas Scientific pH probe this is what they told me to try and it worked for me:

saturate a glass of water in pure NaCl salt and soak the probe in it for a day (24 hours) to restore the electrolyte and that worked great for me. For the Apex probe I think you should use KCl salt instead of NaCl. If it still acts a bit funny after that soak it in 4pH calibration solution for another 24 hours. If it still seems untrustworthy after that, replace it

 

[Raintree Aquatics]

I have been struggling to get my Neptune pH probes to work on my system. The pH will randomly drift from a reasonable number to 12.2 over the span of 3-12 hours. I will unplug the probe and the display will continue to read in the low 12s.

I initially thought it was a faulty probe so I replaced it with a new one but the same thing happened. I tested the probe isolated from the aquarium in a small cup of tank water with no success.

Neptune systems has not been helpful basically saying they’ve never seen something like this before and it must be a setup issue.

Has anyone experienced this and can help identify what may be wrong?

Thanks!

Have you tried to do a manual calibration on the probe. If not, give that a try.