Help needed with KH Director

[Kenny311]

I've switched from Apex to GHL. So far it has been a positive experience and Vinny has been very helpful. I am however having issues getting an accurate reading from the KH Director. I am sure it must be user error. Hoping someone here can help.

After reading multiple post this morning I started anew with the KH Director as I try to get an accurate reading for the KH Director. First I disconnected the sample water line from the dosing pump.
I emptied the water in the water line into a graduated cylinder and got a measurement of 25ml. The line with the filter installed measures 77". If I am following the directions correctly I add to the 77" + 4.7 + 6.3 = 88. When I enter that into the calculator I get a calculated volume of 35 ml.

What I did notice as I manually primed the sample water line is that after every couple of revolutions I get a fair sized air bubble coming thru the line. I am not sure if that is normal.

I did also calibrate the probe again.

Any suggestions would be helpful.

 

[wildcrazyjoker81]

I personally to get mine spot on needed to just fill each tube and empty them into the graduated cylinder as measuring just didn't seem to ever be accurate for me. The air bubbles are more than likely coming from the air filter. Run the first dosing head and kinda shake/flick the filter and see if you can see air bubbles come out of it.

 

[Kenny311]

CrazyJoker,
Thanks for the response. So take the line from the sump to the filter. Fill it and put in graduated cup. Take rest of line from top of filter to pump head, Fill it and put in same cup. Measure results?

 

[Lasse]

CrazyJoker,
Thanks for the response. So take the line from the sump to the filter. Fill it and put in graduated cup. Take rest of line from top of filter to pump head, Fill it and put in same cup. Measure results?

If you do it that way - you need to add the volume of the filter too - 7 ml. Otherwise - just measure your total tube length and use the inbuild tool in order to calculate

Sincerely Lasse

 

[Kenny311]

Lasse,
Thank you for the response. But I get wildly different numbers depending on how I do it. Here is what I mean. When I emptied the water in the water line ( including the filter) into a graduated cylinder and got a measurement of 25ml. The line with the filter installed measures 77". If I am following the directions correctly I add to the 77" + 4.7 + 6.3 = 88. When I enter that into the calculator I get a calculated volume of 35 ml. There is a difference of 10ml.

 

[Lasse]

Whats your inner diam of the tube - in mm?

I would use the measured value - if you are sure its right - but you need to get out all water from the filter

Sincerely Lasse

 

[Kenny311]

I’m using the tube that came with Kd Director. So 4mm.
When I emptied the contents from the line I blew in the tube to make sure all the water came out.

 

[Lasse]

Just to be sure - the 4.7 and 6.3 are the pump tube and the connection from the pump to the KH director length - am I right? If so you need to empty them also from water. Have you this amount in your measurements of 25 ml?

When I do my calculation - I take all tube length (not the filter length) KH - director to pump - tube through pump - incoming to the filter and filter to the end and add 7 ml (filter capacity)

Sincerely Lasse

 

[Kenny311]

Just to be sure - the 4.7 and 6.3 are the pump tube and the connection from the pump to the KH director length - am I right? If so you need to empty them also from water. Have you this amount in your measurements of 25 ml?

When I do my calculation - I take all tube length (not the filter length) KH - director to pump - tube through pump - incoming to the filter and filter to the end and add 7 ml (filter capacity)

Sincerely Lasse

Lasse,
Ok. I followed your directions and added all the tube lengths. That gives me 86.5 inches. So that volume comes out to 28ml. I added the 7ml for the filter and get 35ml. I will use that. Thank you for all your assistance.

Best Regards,
Ken

 

[Lasse]

I hope its work well - this is the way I have done it.

Sincerely Lasse

 

[BeanAnimal]

I think far too big of a deal is being made of the sample line calibration and its purpose is not well explained in any of the setup videos or by any of the talking head youtubers...

First - like any doser you must calibrate the doser head itself, with its full length of hose and filter attached and all air removed from the entire lineset. This has nothing to do with the tubing volume, but only tells the unit how many ml per revolution the doser head and associated tubing can deliver.

The second part of this where one must calculate the actual tubing volume, filter volume, etc. is what people are making far too complicated because they don't understand the purpose.

After each test, the sample head is run backwards to fully empty it so that when the next test starts, there is no OLD water in the sample. To do this, the KH director needs to know how much water is IN the line.

So use the calculator or graduated cylinder or whatever to get close. Then watch the measurement take place. When the measurement is DONE watch the tubing being evacuated. If the tubing does not fully empty, you need to add volume to your calibration volume measurement. If the tubing empties and stream of bubbles are pushed out of the end then you need to reduce value used for calibration volume measurement.

You don't need to stress about precision calculations... just get close and then adjust based on what you see.


Hope that helps...

 

[Kenny311]

BeanAnimal,
Thank you! I know something is wrong. However I don't know what it is. I did multiple test today with Hanna, Red Sea and GHL. Hanna and Red Sea were within .02 of each other. GHL was 2.7 off of both of these.

I've decided that this week I will start from step one. Disconnecting the KH Director all the lines and starting from step one.

Frustrating but I can't yet accept that Hanna and Red Sea are both wrong and blindly accept GHL numbers.

 

[XavierZ06]

Hey Kenny, any luck dialing yours in? Going through the same struggle and no matter how many times I recalibrate or re-measure, the values don't change. I'm 100% positive I have the right inputs but still my KH Director reads 1-1.5 DKH low every time.
Thing is about to go out the window at this point.

 

[BeanAnimal]

I am actually doing a re-call today. Readings have been very consistent, but ~2 dKh higher than red sea pro.

I have a decent balance, but not 100% sure that weighing calibration is that accurate without a very precise balance, given the very small calibration volume/weight.

I purchased 5ml and 10ml high quality graduated cylinders as a sanity check. Will report back.

 

[Kenny311]

Hey Kenny, any luck dialing yours in? Going through the same struggle and no matter how many times I recalibrate or re-measure, the values don't change. I'm 100% positive I have the right inputs but still my KH Director reads 1-1.5 DKH low every time.
Thing is about to go out the window at this point.

Xavier, yes I finally got mine to work. No small task. Here is what I finally did to get mine to work. First thing I did was recalibrate the probe. Next I changed location of sample intake line. I tied it to one of the down pipes in my sump and removed the tube from the bottom of the filter. I then ran the doser head one and watched as it pulled sample water. I made sure that there were minimal bubbles in the tube. I also purchased ATI Referenz solution. Ran the test using Referenz as sample. Result was within .2 dkH. DM me if you want to discuss