KH Director

[Dogtown]

Good news! Well partially good news. Marco's steps resolved the air exchange/vent issue. The #3 tube no longer pops off. I watch the vent tube closely and can see that it draws air in and sometimes pushes air out freely. I also changed out the doser #3 tube, shortened it, and primed them all per suggestions. Thanks all!

Took two measurements since and the KHD is still erroring out with "OK Error: Titration takes too long". I'm not seeing the PH value drop much while the reagent is being added.

 

[Dogtown]

After taking three measurements, all three result in OK Error: Titration takes too long. This KHD unit had been running fine for several weeks before I ran out of reagent. Then I left it alone for a few weeks waiting for my reagent and then this happened. It must be something I'm doing wrong.

PH value during the water sample phase starts at 1.7 and rises to 7.2. When the reagent addition phase starts, the PH value doesn't drop as Ditto mentioned it should. After several minutes I get the error. This seems odd because the reagent is definitely being added. I can see it being drawn from the dosing container. I even allowed a small bubble of air into the line so that I could follow the bubble up the tube and into the KHD. What next?

 

[Support@GHLUSA]

Did the probe sit dry during the time the unit was not testing?
I would start with a probe recalibration. Maybe even pull the probe out, and let it sit in RODI water for an hour or two...

In addition, you mentioned the probe pushed out when water enters the chamber, the first item there is the vent, but also make sure you tighten the bulkhead nut, more. The probe should be snug and not move.

Also while you're testing, you can drop the sample volume down to 60mL - this will cut the test time down.

 

[Dogtown]

Did the probe sit dry during the time the unit was not testing?
I would start with a probe recalibration. Maybe even pull the probe out, and let it sit in RODI water for an hour or two...

Its hard to say if the PH probe was dry or not but it seems like a real issue. I have already calibrated the probe 3 times over the last couple of days and it adjusts to approximately these numbers each time. Still, if it was dry I see where you are going.

I will do as you suggest. Pull the probe out, let it sit in rodi water for a couple of hours, calibrate again and then retest. Thanks.

 

[Dogtown]

I let the PH probe sit in RODI for 5 hours and then calibrated it again. No improvement unfortunately.

The PH value starts at 1.8 and increases to around 7.9 when the water sample is added. During the reagent add phase the PH value only drops to around 7.7. During the waste water removal phase, the PH value drops all the way back to around 1.8.

What is the typical PH value you all see during your reagent addition phase?

 

[Buddah001]

Does anyone have any idea to not have my P4’s turn yellow blinking due to the water sample and flush of the cell of the KH not being full on the doser pump?

I was wondering why it was always blinking yellow and with the software updated on both P4 I was able to figure out why.

View attachment 765415

1 and 3 are used by the KH doser, even thou alarm in them is off. Dosing 9 I was setting up for AWC.

View attachment 765418

@Ditto did you ever figure out how to disable this?

 

[Ditto]

@Buddah001 - Alas no I just use the GHL app and refill my container.

 

[Mortie31]

During the test, when the reagent is added a small circulation pump runs, can you feel small vibrations in the tubes? You can sometimes even see them vibrate.

 

[reefwiser]

During the test, when the reagent is added a small circulation pump runs, can you feel small vibrations in the tubes? You can sometimes even see them vibrate.

This happens when the pump is pushing fluid thru the lines. Are you having a problem with the pump sucking up the fluid from the container?

 

[Mortie31]

This happens when the pump is pushing fluid thru the lines. Are you having a problem with the pump sucking up the fluid from the container?

No not having a problem, my circulation pump broke a few months ago. It mixes the reagent with the sample water in the internal chamber, and can be felt / heard when it’s running.

 

[reefwiser]

Yes,the peristaltic pumps are small rollers squeezing a piece of tubing as the motor spins around and around. This will cause the line to move as the fluid runs thru the tubing one squeeze at a time.

 

[Mortie31]

Yes,the peristaltic pumps are small rollers squeezing a piece of tubing as the motor spins around and around. This will cause the line to move as the fluid runs thru the tubing one squeeze at a time.

No not the peristaltic pumps, there is a small circulatory pump inside that mixes the reagent with chamber water

 

[Buddah001]

Yep my shakes to when it is testing. As if it is mining the reagent and water to measure the ph

 

[Buddah001]

@Buddah001 - Alas no I just use the GHL app and refill my container.

How do you stop the alarms then? I understand how to stop the blinking yellow light but these should not be an issue since they are the supply and waste water fow the KHD? They should set it up so that those 2x dedicated pumps do not trigger a warning

 

[Mortie31]

Yep my shakes to when it is testing. As if it is mining the reagent and water to measure the ph

It is, there is a tiny cylinder circulation pump that mixes the liquids.

 

[Mortie31]

How do you stop the alarms then? I understand how to stop the blinking yellow light but these should not be an issue since they are the supply and waste water fow the KHD? They should set it up so that those 2x dedicated pumps do not trigger a warning

I set the container size to 30000ml and that way they don’t alarm/warm as often

 

[bhuyett]

Sorry if this has been asked already. But I just received my replacement PVC tubing from GHL. Does this just replace the Reagent tube from the Doser to the bottle then?

 

[Mortie31]

Sorry if this has been asked already. But I just received my replacement PVC tubing from GHL. Does this just replace the Reagent tube from the Doser to the bottle then?

Yes mate

 

[Mortie31]

Yes mate

Sorry and from the doser to the KHD

 

[yepreef]

The pushing off the doser has happen to me, the chamber you have to empty your waste water and the overflow waste water Are the tubes above water? I had an issue where my one waste container filled for the KH and it blew the hoses off.

On one of my KH I also noticed the tubes were not snug on the connectors, others have posted this and like them I zipped tied mine.

View attachment 786572

Where did u get those ziptie? does it work well for u? mine sometimes felt off