GHL pH probe needs frequent calibration

Reefer911 · Aug 28, 2023

This has been an ongoing issue. New GHL pH probe needs calibration every time I turn off the return pump for maintenance, and that is weekly. The majority of the time I just let it go and let it read how it wants…in the 4-5 range and spot check with my Hannah pen to make sure…and of course the pen reads 8.3.

Is this common? I have moved the probe to a different area of the sump with zero changes.

n2585722 · Aug 28, 2023

I don't think that is normal.I have no experience with that controller but on mine the last several days I have had my return pump off since I installed a flow sensor. Each time I cannot see where it made much difference if at all and my pH probe is in the sump near the return pump. Here is a graph with the return flow overlayed with pH. The orange is the flow sensor. It was installed on the 24th and the return was off for a while while installing it since I also gave the pump a good cleaning at that time which was a couple of hours. Also the pump has been off since a couple of times.

Reefer911 · Aug 29, 2023

It can’t be normal. Last night I turned off the pump and added some copepods. And then this. I can’t recalibrate every time I turn the pump off so I have to live with an errant reading

n2585722 · Aug 29, 2023

Reefer911 said:
It can’t be normal. Last night I turned off the pump and added some copepods. And then this. I can’t recalibrate every time I turn the pump off so I have to live with an errant reading

Do you have a different probe you can try?

Reefer911 · Aug 29, 2023

Maybe. I think I purchased this one because the other one wasn’t working, or something like that
I had already decided to try the old one tonight when I get home

Vinny@GHLUSA · Sep 1, 2023

Reefer911 said:
It can’t be normal. Last night I turned off the pump and added some copepods. And then this. I can’t recalibrate every time I turn the pump off so I have to live with an errant reading

Why "live" with it?

Open a support ticket so we can help you out.

Reefer911 · Sep 1, 2023

Vinny@GHLUSA said:
Why "live" with it?

Open a support ticket so we can help you out.

Good question haha.

Reefer911 · Oct 8, 2023

Vinny,
As you know I responded to your email and provided you with everything you asked. This was over a month ago and you never responded back. What was the purpose of the support ticket if there’s no support?

The pH probe continues to suck

MabuyaQ · Oct 9, 2023

Did you check for stray voltage, also electromagnetic interference can influence pH probes causing strange behaviour.

Reefer911 · Oct 9, 2023

I will try to do that today. Im assuming there should be zero stray voltage correct?

gbroadbridge · Oct 9, 2023

Where is the probe located?

It needs flow, but not turbulence.

Air bubbles will disturb it, as can induced voltage if the probe lead is routed close to sources of electrical interference.

Steve2020 · Oct 9, 2023

How long does it take for probe reading to drop when turning off the return pump? Is it instantly or over a short period of time? Run this test and see if it does the same thing. Rinse the probe in RODI water and ensure it is dry. Then put it in one of the calibration fluids ensuring it is reading properly, if not then calibrate it, then turn your pump off and see if the PH changes.
Something else, is the probe in your sump? Do you have a skimmer and if so do you leave it running or turn it off when your return pump is not running?

Reefer911 · Oct 9, 2023

gbroadbridge said:
Where is the probe located?

It needs flow, but not turbulence.

Air bubbles will disturb it, as can induced voltage if the probe lead is routed close to sources of electrical interference.

I have moved the probe around over the last few months and it’s currently in the return chamber. There are no air bubbles, or anything growing on the probe. I cleaned the probe last night per GHL’s cleaning instructions…50/50 white vinegar and warm water

I will double check that the probe wire isn’t routed too close to any other wires, but I do know it’s running next to my temp and conductivity probe wires

Reefer911 · Oct 9, 2023

Steve2020 said:
How long does it take for probe reading to drop when turning off the return pump? Is it instantly or over a short period of time? Run this test and see if it does the same thing. Rinse the probe in RODI water and ensure it is dry. Then put it in one of the calibration fluids ensuring it is reading properly, if not then calibrate it, then turn your pump off and see if the PH changes.
Something else, is the probe in your sump? Do you have a skimmer and if so do you leave it running or turn it off when your return pump is not running?

IIRC, it will count itself down, or up, depending on what it feels like doing (it seems)

I do know when I calibrate the probe with 9pH solution, the probe reads exactly 9.

The skimmer is always turned off just riot to turning the return pump off

Steve2020 · Oct 9, 2023

Reefer911 said:
IIRC, it will count itself down, or up, depending on what it feels like doing (it seems)

I do know when I calibrate the probe with 9pH solution, the probe reads exactly 9.

The skimmer is always turned off just riot to turning the return pump off

After calibration, put the probe in the 9.0 solution. As you said it reads 9.0. Then turn off your return pump while the probe is in the 9.0 solution. Does the ph remain constant or does it change?

Reefer911 · Oct 9, 2023

Steve2020 said:
After calibration, put the probe in the 9.0 solution. As you said it reads 9.0. Then turn off your return pump while the probe is in the 9.0 solution. Does the ph remain constant or does it change?

Ok I will try that tonight

Vinny@GHLUSA · Oct 9, 2023

Reefer911 said:
Vinny,
As you know I responded to your email and provided you with everything you asked. This was over a month ago and you never responded back. What was the purpose of the support ticket if there’s no support?

The pH probe continues to suck

Support is handled via the ticket system, not email.
What is your ticket number?

To my knowledge, all tickets have been replied to. If there are any that we reply to and it goes without a response, the ticket is closed by the system after 14 days.

Reefer911 · Oct 9, 2023

Vinny,

Now I’m even more confused. I submitted a ticket and you responded…via email. If tickets aren’t handled via email, then why did I get an email from you regarding my ticket???

Furthermore, I responded back and gave you the requested info within a day and never heard back.

Ticket number 7659

Vinny@GHLUSA · Oct 9, 2023

Can't reply to a post that we don't see. The last message was from me. Your reply was not posted and therefore the ticket was closed. Reply there with the requested info so we can continue.