Question: Ph Probe calibration issue.

[JHSteepat]

My pH probe won't hold calibration.

I have Pinpoint Probe on a hydros system. I calibrate my probe using the Pinpoint packs (pH 7/10), or some Amazon-bought calibration fluid, and get the same results. Same thing happened when I replaced to probe with a new one.

When I calibrate, my pH is between 8 and 8.1, with ~0.1 daily swings. The sensor is great for me to visualize the swings. However, over a number of weeks, the pH can be seen to gradually increase (according to the readout) to between 8.5 and 8.7, at which point I re-calibrate, and it returns to 8.0-8.1.

Is this normal? Do I need to use a different brand probe? I can't see relying on this to control anything in the tank such as a Ca reactor.

 

[JHSteepat]

Anyone……

 

[william Lutman]

Do a second check with another tool. Maybe it's correct

 

[TehBrainz]

Where do you have your probe placed?

Be sure it isn't collecting microbubbles or algae/schmutz

 

[JHSteepat]

In sump. Maybe I’ll move it to a different place. It may be a little close to a heater and skimmer.

 

[redfishbluefish]

As stated, try a different location...you might be getting electrical interference. The other thought is to clean the probe. Soak in vinegar or citric acid overnight and then rinse and re-calibrate.