KH Director Reading 0 - seems to be a pH probe issue

CSAXE21 · Mar 16, 2023

Hi all,

I've filed a ticket with GHL but wanted to see if any others have had/resolved the issue in the meantime in hopes of getting my KH Director back up and running.

Profilux 4 and KH Director purchased October 2022 and setup shortly after. Has been working perfectly for the past few months since, until this week my KH Director started reading 0 dkh. Testing the dosing heads and they all seem to work fine. Read online that it could be due to buildup on the pH probe so to clean and calibrate. There didn't seem to be much gunk on it, but upon calibration found that it would calibrate "successfully" but not actually change the reading. Both ADC1 and ADC2 read 65518 and the pH is flat at 0. I've tried unplugging it and rebooting the system as well with no luck.

Any suggestions would be appreciated!

Lasse · Mar 16, 2023

Are ADC2 and ADC1 the same - something is very wrong. ADC2 and 1 are the two endpoints the inbuild pH meter use for calculate the right pH. Are you sure you not mixed up the calibration fluids?

Check the BNC connection too and recalibrate

Sincerely Lasse

CSAXE21 · Mar 16, 2023

Lasse said:
Its ADC2 and ADC1 the same - something is very wrong. ADC2 and 1 are the two endpoints the inbuild pH meter use for calculate the right pH. Are you sure you not mixed up the calibration fluids?

Check the BNC connection too and recalibrate

Sincerely Lasse

Hi Lasse,

Thanks for the reply. Positive that the fluids were not mixed up and I’ve tried to recalibrate several times. Here’s what I see on my app now. I’ll try the connection again.

CSAXE21 · Mar 16, 2023

Lasse said:
Are ADC2 and ADC1 the same - something is very wrong. ADC2 and 1 are the two endpoints the inbuild pH meter use for calculate the right pH. Are you sure you not mixed up the calibration fluids?

Check the BNC connection too and recalibrate

Sincerely Lasse

Confirming that the connection is good and recalibrating gave the same results

Lasse · Mar 16, 2023

Sometimes there can be oxide in the BNC connection. The BNC connection is the connection between the electrode and the KH director. If you turn the electrode's BNC connector back and forth into the KH director's connector (a few times) and test afterwards. Another option is that the electrode has been broken

Sincerely Lasse

CSAXE21 · Mar 16, 2023

Thanks Lasse. Is it normal to break in less than 6 months? Any risk in your opinion that this could be a broader KH Director issue?

Lasse · Mar 17, 2023

I´m not sure what´s happens with your KH director (or the probe) but I have used KH:s type of pH electrodes for years without problem. Both at home and at my former job. So - I do not think is normal. But it seems as there is no contact between the electrode and the electronics of the KH director. I´ll think you should await the response from the ticket system.

Sincerely Lasse

BeanAnimal · Mar 18, 2023

I would hard boot everything.

I would then hop into calibration and just confirm that I see the ADC value changing as I dip the probe in different solutions.

I would plug the regular working tank PH probe into the kH director and see if the ADC reading changes as in and out of tank water or calibration solution as well.

Lastly, I may try the KH probe on the tank PH port to see if readings change there as the probe is put in and out of solution.

Between those 2 or 3 tests it will be fairly easy to rule in or out the probe or the port.

Simply__J · Jul 2, 2023

Any solution? This is EXACTLY what I'm experiencing.

BeanAnimal · Jul 2, 2023

Reboot everything. I guess the KH director flakes out sometimes. Has happened to me 3 times. Rebooting everything has fixed it each time.

MileZer0Reef · Jul 14, 2023

This has happened to me 3 times and I’ve shipped it back and they replace the main board, ship it back, and it breaks again in another week. Did you find a solution?