Experience with GHL KH Director -- SOS

[esther]

So, I've been having a heck of a time getting this thing to be consistent. All day yesterday it would say that dKH was 8. I tested with Hanna and it was at 9, so I decided I'm going to go through the entire process of setting it up & calibrating everything again.

I'm now on my third round of going through the entire setup process, so I figured I'd document every step I'm taking to see if I can finally get the KH Director to be a reliable piece of equipment.

1. Watched KH Director Initial Setup (Part 1) on YouTube :
2. Watched KH Director Initial Setup (Part 2) on YouTube :
3. Watched KH Director Initial Setup (Part 3) on YouTube :
4. Re-Read the KH Director Water Filter Manual
5. Re-Read the KH Director Instruction Manual

After doing all this, the tests are coming out at 6.4, 6.3, 5.4, etc.

One thing that I did that made the test actually show an accurate number is I primed the water sample to come up almost to where it goes into the KH Director. My theory is that the KH Director isn't getting enough of a water sample to accurately test. I'm at a loss for what to do. I've remeasured all tubing, recalibrated all pumps. Any suggestions on what to do next? Do you think I have a bad KH Director?

@Vinny@GHLUSA @Matthias Gross @Ditto

#ghl #KHDirector

 

[Crimsonvice]

So, I've been having a heck of a time getting this thing to be consistent. All day yesterday it would say that dKH was 8. I tested with Hanna and it was at 9, so I decided I'm going to go through the entire process of setting it up & calibrating everything again.

I'm now on my third round of going through the entire setup process, so I figured I'd document every step I'm taking to see if I can finally get the KH Director to be a reliable piece of equipment.

1. Watched KH Director Initial Setup (Part 1) on YouTube :
2. Watched KH Director Initial Setup (Part 2) on YouTube :
3. Watched KH Director Initial Setup (Part 3) on YouTube :
4. Re-Read the KH Director Water Filter Manual
5. Re-Read the KH Director Instruction Manual

After doing all this, the tests are coming out at 6.4, 6.3, 5.4, etc.

One thing that I did that made the test actually show an accurate number is I primed the water sample to come up almost to where it goes into the KH Director. My theory is that the KH Director isn't getting enough of a water sample to accurately test. I'm at a loss for what to do. I've remeasured all tubing, recalibrated all pumps. Any suggestions on what to do next? Do you think I have a bad KH Director?

@Vinny@GHLUSA @Matthias Gross @Ditto

#ghl #KHDirector

Did you measure and input the length of sample line(+ filter+ length past dosing head)?

 

[esther]

Did you measure and input the length of sample line(+ filter+ length past dosing head)?

Yup! Like 3 times. I'm thinking I may just shorten the line and put it somewhere else in the sump. I really just don't know what to do anymore.

 

[Crimsonvice]

Yup! Like 3 times. I'm thinking I may just shorten the line and put it somewhere else in the sump. I really just don't know what to do anymore.

Just out of curiosity is it a new or used unit? I purchased a used doser 2.1 to use with my KHD and the reagent doser head wasn't working right. I almost gave up on it working until someone suggested changing the dosing pump from 2 to 4, and everything worked like a charm. Now I just need to buy a new dosing head... Lol

 

[esther]

Just out of curiosity is it a new or used unit? I purchased a used doser 2.1 to use with my KHD and the reagent doser head wasn't working right. I almost gave up on it working until someone suggested changing the dosing pump from 2 to 4, and everything worked like a charm. Now I just need to buy a new dosing head... Lol

Everything brand new.

 

[esther]

@Crimsonvice any idea how to get all air bubbles our of the water sample line? Maybe that could be it? There are definitely some bubbles here and there.

 

[AZMSGT]

@Crimsonvice any idea how to get all air bubbles our of the water sample line? Maybe that could be it? There are definitely some bubbles here and there.

The line gets emptied every time it’s used. When emptied it will get air in it. However If you get air in it during testing then it’s pulling air from the sump or where it’s at in the sump. Watch the line as it pulls a sample. DO NOT PRIME the sample line.

To help improve the sample
Put the filter on the end of the sample line in your sump.
weigh it down and have it near the bottom of your sump in a bubble free area.
I weighed mine down by using a zip tie and a piece of scrap PVC.
seal all line connections with small zip ties

Don’t forget, Don’t worry about what the KHD reads compared to your hanna test.

 

[esther]

The line gets emptied every time it’s used. When emptied it will get air in it. However If you get air in it during testing then it’s pulling air from the sump or where it’s at in the sump. Watch the line as it pulls a sample. DO NOT PRIME the sample line.

To help improve the sample
Put the filter on the end of the sample line in your sump.
weigh it down and have it near the bottom of your sump in a bubble free area.
I weighed mine down by using a zip tie and a piece of scrap PVC.
seal all line connections with small zip ties

Don’t forget, Don’t worry about what the KHD reads compared to your hanna test.

So, are you saying that instead of having KHD > Tube > Water Filter > Tube into Sump... I can remove the tube in between the KHD and just put the filter at the end of the sample line directly into the sump?

 

[esther]

The line gets emptied every time it’s used. When emptied it will get air in it. However If you get air in it during testing then it’s pulling air from the sump or where it’s at in the sump. Watch the line as it pulls a sample. DO NOT PRIME the sample line.

To help improve the sample
Put the filter on the end of the sample line in your sump.
weigh it down and have it near the bottom of your sump in a bubble free area.
I weighed mine down by using a zip tie and a piece of scrap PVC.
seal all line connections with small zip ties

Don’t forget, Don’t worry about what the KHD reads compared to your hanna test.

Also, I only worry about how it compares to Hanna when it's way off and I get an alarm. 5.3 dKH is def no where near 9 dKH.

 

[AZMSGT]

So, are you saying that instead of having KHD > Tube > Water Filter > Tube into Sump... I can remove the tube in between the KHD and just put the filter at the end of the sample line directly into the sump?

Khd>tube>doser>tube>filter in water weighed down. Just not on the very bottom. You don’t want it sucking up junk.

 

[AZMSGT]

Here is my set up. Nothing fancy, The red thing is my filter. No it’s not the same as GHLs white one. I accidentally crushed my GHL one and I used what I had on hand as a replacement. The red one is for large scale RC airplanes, it worked for me when I needed it after I goofed.

 

[esther]

@AZMSGT thanks for the tip. Gonna add it to the list of things to try to see if I can get this thing working.

 

[Crimsonvice]

I agree with what @AZMSGT said.

Comparing testing equipment to testing equipment can be hard. If you have a reference solution, you can test both devices that way. I know GHL has a 7.5 dkh solution you can buy just to double check if both devices are comparable. Just remember that each unit has a +/- variant.

 

[griff500]

Make sure that waste and vent tubing aren't below water level.

 

[esther]

Make sure that waste and vent tubing aren't below water level.

They're not. They empty into a large glass cyclinder at the top.

 

[JKenny]

esther, I do empathize with you... I'm a couple of weeks into installing the KH Director myself and have had similar troubles.

I had been seeing very inconsistent readings but I've now been stable for 2 days, testing 4x/day, and reading within .1 of the Hanna so I think I'm good now. All I can share is that I ended up calibrating the pump speeds and the PH probe 3 different times and moved the intake tube around to a few places in the sump - with the GHL filter at the end of the intake line submerged in the sump.

Not certain which change made the difference - but hang tough, it's there somewhere...

Also, I see that you're using a different filter on the intake line. How are you calculating the "ML" volume of that filter?

 

[esther]

esther, I do empathize with you... I'm a couple of weeks into installing the KH Director myself and have had similar troubles.

I had been seeing very inconsistent readings but I've now been stable for 2 days, testing 4x/day, and reading within .1 of the Hanna so I think I'm good now. All I can share is that I ended up calibrating the pump speeds and the PH probe 3 different times and moved the intake tube around to a few places in the sump - with the GHL filter at the end of the intake line submerged in the sump.

Not certain which change made the difference - but hang tough, it's there somewhere...

Haha. Hope to find it soon. It's been testing every hour and hasn't gone above 6.1 dKH.

 

[AZMSGT]

esther
Also, I see that you're using a different filter on the intake line. How are you calculating the "ML" volume of that filter?

It’s my filter and I just used the length of it and added it to the tube length after it was installed in the tube. Simple.

 

[AquaPhilNJ]

Instead of measuring the sample water tube with a ruler, you can fill it with water and then while pinching it place the tube over a graduated cylinder and then measure the exact ml of water that comes out.
Second, the calibration solution someone else mentioned is something I also recommend.
For me the #1 calibration issue is the KH reagent being 100% calibrated to the tenth of a ml and absolutely having no air bubbles in the tube.

 

[JKenny]

Just a thought...

GHL computes the milliliters volume of their intake tube based on a 4mm internal diameter tube. You tell it the length of your tube and it converts that to a "ML" volume - and then advise you to just add 7ml to your total calculation to allow for the GHL filter volume.
Perhaps, if the RC filter is larger/smaller than 4mm internally then the "sample tube ml" amount would need to be adjusted?