PH calibration?

Mydoghasfleas · Dec 18, 2019

So I have a new Apex and probe. I tried to calibrate with the 7 and 10 solutions. And after calibration I left it in the 10 to make sure it was accurate. It is reading about 0.5 too low immediately after calibration in the 10 pack.

I calibrated in apex fusion. The probe has been sitting on a shelf for about one year, boxed in the original box inside in my room out of direct sunlight. I did notice before taking the plastic tip off that there was not much fluid. Could this be a problem with the probe.

attached is a pic of the reading immediately after calibration, while still in the 10 cal fluid.

rkpetersen · Dec 18, 2019

If the probe tip dried out, that could be a problem, definitely.
Generally when a probe dries, it's recommended to recondition it with the electrolyte solution.
However, sometimes it's just a matter of letting it sit in flowing tank water in the sump for a few days before calibrating.
Also, when you calibrate, there are a few tips to make sure it goes properly.
First, do a manual calibration, not automatic.
Then for each step, wait an extra long time until the number is absolutely not changing, before going to the next step.
Also, the 7 and 10 solutions should be at tank temp.
Easiest way to do this is place the packet upright in a water bath, which itself then sits in the tank water.
Make sure that the probe is swished around several times during each calibration step.
Hopefully if you follow these steps, you'll get good numbers.

And almost everyone needs more than the one set of standard packets that Neptune provides.
You don't have to purchase additional standards from Neptune; any 7 and 10 pH packets will work.