KH Director

[Ditto]

I saw the announcement of the KH testing solution coming in a few weeks which is great we will now be able to test our unit from known test source.

I am wondering if the line is pinched inside the unit? I know I had to unpinch mine and repinch it when my readings started to go off and it began working, and been fine ever since?

The other issue I had was the dosing container I was using did not have a good deal on the dosing line and after dosing the line would actually fall 1/4”.

Hopefully someone from GHL support is
PMing you go assist

 

[Vinny@GHLUSA]

Hey Guys! I just fired up a 2.1 and plan on a director down the road. I have a couple of questions, I see the complementary temp probe/ does that allow me to control a heater via a power bar? also the Float/sw inputs and the stirrer outputs can I use them for other purposes, say a relay or a push button

The temperature probe is for monitoring only. Level sensor inputs are for ATO or AWC purposes only; the dosing heads are used for these tasks.
If you want control-options, that is more into the grounds of a controller system; ProfiLux Mini or ProfiLux 4.

 

[Vinny@GHLUSA]

If I remember correctly mine falls to 4ish, but I guess it depends on your tank ph as well mines 8.3. I don’t think the actually values matter just that when the sample water is added it should match your tank ph and then you can watch it fall as reagent is added.

The shown pH value in the KHD will not match the tank's pH level. Why?
Because it's a modified pH probe designed to work within the KHD specifications.

When a KH test occurs, the water sample is added to the measurement cell, pH rises temporarily due to tank water sample...that's normal.
Once reagent is added, pH drops...that's normal too.
KHD waits for pH to drop to a certain level before interpreting the data and providing a KH result.

If you need to test the KHD probe, you have the diagnostics section in the KHD settings page.
Dip the probe in pH 4 and pH 7 solutions to verify the upper and lower range calibration accuracy.
If the readings are outside of the +/- 0.1 accepted range, you should recalibrate.

 

[Mortie31]

The shown pH value in the KHD will not match the tank's pH level. Why?
Because it's a modified pH probe designed to work within the KHD specifications.

When a KH test occurs, the water sample is added to the measurement cell, pH rises temporarily due to tank water sample...that's normal.
Once reagent is added, pH drops...that's normal too.
KHD waits for pH to drop to a certain level before interpreting the data and providing a KH result.

If you need to test the KHD probe, you have the diagnostics section in the KHD settings page.
Dip the probe in pH 4 and pH 7 solutions to verify the upper and lower range calibration accuracy.
If the readings are outside of the +/- 0.1 accepted range, you should recalibrate.

@Vinny@GHLUSA sorry if I’m mistaken but surely the KHD ph probe is measuring the ph of the water sample and surely before the reagent is added the sample ph will read the same as the tank ph. It does in mine anyway

 

[scuzy]

Well mine started giving me titration taking too long. checked everything. recalibrated pumps and the probe. not sure what else to check.

 

[Derek Clifford]

Can anyone share their add-on control settings for Triton core 7? What ml per dkh have you got?

Also is there a minimum calculated adjustment the kh director will make? I have target 7 dkh, current reading of 6.7 dkh. I have add on control at 1ml per 1 dkh. KHD is showing 0 in calculated adjustment and I cannot tell if KHD has been making adjustments.

Without being able to see historical measure or dose data I am hesitant to let the KHD loose on its own.

 

[kodo28]

Some comparative numbers against some home tests kits ?

I've been facing 1 dkh difference between RedSea Alk Kit / RedSea Alk Pro kit.

Both kits are reading 9 dkh against 8 dkh from Kh Director.

Tested many time same numbers on both sides.

Kh Director probe, is well calibrated and reading 4 and 7 ph on calibration process.

Dosers heads are also well calibrated.

 

[tastyfish]

Can anyone share their add-on control settings for Triton core 7? What ml per dkh have you got?

Also is there a minimum calculated adjustment the kh director will make? I have target 7 dkh, current reading of 6.7 dkh. I have add on control at 1ml per 1 dkh. KHD is showing 0 in calculated adjustment and I cannot tell if KHD has been making adjustments.

Without being able to see historical measure or dose data I am hesitant to let the KHD loose on its own.

Triton core7 alk is 19500dkH per 1000ml (1l)

 

[Matthias Gross]

Some comparative numbers against some home tests kits ?

I've been facing 1 dkh difference between RedSea Alk Kit / RedSea Alk Pro kit.

Both kits are reading 9 dkh against 8 dkh from Kh Director.

Tested many time same numbers on both sides.

Kh Director probe, is well calibrated and reading 4 and 7 ph on calibration process.

Dosers heads are also well calibrated.

Hi

I understand your concern, this question is asked many times.
This is normal, you don't need to be worried, I am sure your calibration is perfect, your KHD works correctly.
We did many many tests and depending on the used method we found differences of up to +/- 2°dKH between all tests.

If you prefer to see other values (e.g. because you are used to them) then the KHD offers the option to enter an offset.

Please see also our statement about this in the KHD FAQ:
https://www.aquariumcomputer.com/kh-director-tips-troubleshooting/

Also I want to mention that we offer a KH reference fluid (7.5°dKH, max. tolerance 0.2) to doublecheck the readings and to calibrate the KHD.

 

[Dumaurier7]

@Vinny@GHLUSA sorry if I’m mistaken but surely the KHD ph probe is measuring the ph of the water sample and surely before the reagent is added the sample ph will read the same as the tank ph. It does in mine anyway

How is this possible ? Does your tank pH run between 4 and 7 ?

 

[WWIII]

I used red sea, salifert, hanna when I first got my kh director. None of them matched eachother exactly. The hanna was 1 to 1.5 dkh over the kh director. I then bought a lamotte alkalinity test kit and it matched very closely to the kh director. I use that to double check the kh director (not very often anymore). I have gotten comfortable with the kh director telling me what my alkalinity is over the past 8 months and believe it to be very accurate.

 

[Matthias Gross]

How is this possible ? Does your tank pH run between 4 and 7 ?

There is no water in the cell when the test starts, the shown value of the pH-probe is a random value (probe is in air, not in water).
When the water level rises and eventually touches the pH probe the value starts to move towards the "real" value, as you have it in your tank.
But it will never reach it, due to latency and because the KHD starts to pump reagent into the measurement cell.
-> it is very unlikely that this pH probe will ever show 100% exact the pH of your tank (unless you flushed the cell a few times and then fill the cell manually with water and wait some time until the value has stabilized)

 

[Dumaurier7]

Isn’t there supposed to be some water left behind in the measurement cell to keep the probe moist? So Is this water first extracted then replaced with fresh sample water when the test starts?

 

[Matthias Gross]

yes, a few drops, but they don't touch the probe
the humidity is sufficient to keep the pH probe alive
but not enough to show a reasonable pH value

-> the shown pH value is - as the manual and the FAQs explain - only for diagnosis, e.g. to check the pH probe calibration

 

[Mortie31]

How is this possible ? Does your tank pH run between 4 and 7 ?

Why 4 and 7ph there the calibration fluids and meaningless, I think you must be getting confused, a calibrated probe will measure ph outside of the range of the fluids, it was calibrated against but it may not be as accurate

 

[tastyfish]

@Matthias Gross Do you have any update on the Ca upgrade to the KH Director please?

 

[Dumaurier7]

Why 4 and 7ph there the calibration fluids and meaningless, I think you must be getting confused, a calibrated probe will measure ph outside of the range of the fluids, it was calibrated against but it may not be as accurate

I’m not confused but I understand what you’re saying since I see the same with my Ca reactor . Without any CO2 the pH shown is high but not the same as the tank which means it’s not accurate outside of the range it is calibrated for.

 

[Dumaurier7]

A question for Matthias! is it ok to stir the reagent regularly and before testing ? I am wondering if I should get another one of your stirrers.

 

[Vinny@GHLUSA]

A question for Matthias! is it ok to stir the reagent regularly and before testing ? I am wondering if I should get another one of your stirrers.

No need to stir the reagent. Doing so will provide no added benefits.

 

[Dumaurier7]

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