Experience with GHL KH Director -- SOS

[Ditto]

I been using the KH Director since the beginning, so well over 18 months easily.

How much solution is based on how much testing your going to want to do. I been testing 6 times a day on one tank and 2 times on another and 12 times on a third. Depending on how much you test will determine the overall cost.

I buy the 3 bottle KH Regent Kit because it is cheaper by a few dollars.

I had to replace one probe one one of the three units. About 2 months ago,

I calibrate them all every 3 months.

 

[AZMSGT]

I been using the KH Director since the beginning, so well over 18 months easily.

How much solution is based on how much testing your going to want to do. I been testing 6 times a day on one tank and 2 times on another and 12 times on a third. Depending on how much you test will determine the overall cost.

I buy the 3 bottle KH Regent Kit because it is cheaper by a few dollars.

I had to replace one probe one one of the three units. About 2 months ago,

I calibrate them all every 3 months.

12 times a day!?!? Holy moly

 

[Ditto]

Yes, it a bit of overkill I think 4-6 is really good. Much depends on what you are going to tolerate for your swing and how much is being consumed by your tank. I am working on a project about water changes and the impact on alkalinity consumption so the more test the better.

 

[Xclusive Reef]

12 times a day!?!? Holy moly

So I’m all you testing 20 times a day? If so then you burning reagent like crazy? 1.5 months?

 

[David Cher]

any other reviews on this ?

 

[elcapitan1993]

The best thing to do is to get there 7.5 dkh reference fluid for the KHD it helped me “calibrate” mine correctly, also it does state in the instructions that I will have different readings than other testing devices since it’s more accurate

 

[Kenny311]

I'm having the same issues as @esther. I've been battling the KH Director for two weeks now. So far KH Director has beat me up. I have tried all the suggestions here. Recalibrated all pump heads, moved filter to end of sample line held in place with PVC and a tie-wrap. Measure all lines. Measured contents in sample line (differs from GHL Calculator). I still see a handful of air bubbles when KH Director pulls a sample from sump. KH Director give me a measurement of 6.7 khd. Hanna Checker consistently reads 7.6. Any suggestions would be appreaciated.

 

[Gaël]

I'm having the same issues as @esther. I've been battling the KH Director for two weeks now. So far KH Director has beat me up. I have tried all the suggestions here. Recalibrated all pump heads, moved filter to end of sample line held in place with PVC and a tie-wrap. Measure all lines. Measured contents in sample line (differs from GHL Calculator). I still see a handful of air bubbles when KH Director pulls a sample from sump. KH Director give me a measurement of 6.7 khd. Hanna Checker consistently reads 7.6. Any suggestions would be appreaciated.

Hello,

What do you use for pump calibration? A measuring glass or a precision balance?
Do you calibrate with salt water or fresh water?
Graduating cylinders are generally unreliable and temperature dependent.
The most reliable is the precision balance but using fresh water for calibration

Did you check after the calibration that the pH sensor is displaying 4 and 7 when you dipped it in pH 4 and 7 in the diagnostic area at the bottom of the pH page?

Gaël

 

[BeanAnimal]

I'm having the same issues as @esther. I've been battling the KH Director for two weeks now. So far KH Director has beat me up. I have tried all the suggestions here. Recalibrated all pump heads, moved filter to end of sample line held in place with PVC and a tie-wrap. Measure all lines. Measured contents in sample line (differs from GHL Calculator). I still see a handful of air bubbles when KH Director pulls a sample from sump. KH Director give me a measurement of 6.7 khd. Hanna Checker consistently reads 7.6. Any suggestions would be appreaciated.

There are always going to be an initial handful of bubbles on the initial cycle fill. The is no way around this. The #1 head runs and puts rinse water into the chamber, then it is evacuated by #3 and #1 runs again, this time with the actual water to be sampled. There should be minimal to no bubbles at this point.

Get a scale.01 or.001 gram balance from Amazon ($20) and it will get you far closer than a graduated cylinder of any reasonable cost. If you spend $50-$150 you can get a very nice balance that will find multiple uses in your home and hobby. Use fresh, Distilled or RO water. One decimal place rounded based on two decimals of precision is all that is needed.

 

[Lasse]

KH Director give me a measurement of 6.7 khd. Hanna Checker consistently reads 7.6

Is it a steady difference of around 0.9 in KH? If so - use the correction - start with +10

I use +8%

If you use saltwater and callibrate with a scale - use 1.024 as a correction factor in order to get ml - if freshwater - no need of correction. 6 gr saltwater is 6*1,024 = 6.15 ml

Sincerely Lasse

 

[Kenny311]

Is it a steady difference of around 0.9 in KH? If so - use the correction - start with +10

I use +8%

If you use saltwater and callibrate with a scale - use 1.024 as a correction factor in order to get ml - if freshwater - no need of correction. 6 gr saltwater is 6*1,024 = 6.15 ml

Sincerely Lasse

Lasse thank you. Can you explain why you would need adjust the display measurement? Isn't the whole idea to trust the GHL KD Director?

 

[Kenny311]

There are always going to be an initial handful of bubbles on the initial cycle fill. The is no way around this. The #1 head runs and puts rinse water into the chamber, then it is evacuated by #3 and #1 runs again, this time with the actual water to be sampled. There should be minimal to no bubbles at this point.

Get a scale.01 or.001 gram balance from Amazon ($20) and it will get you far closer than a graduated cylinder of any reasonable cost. If you spend $50-$150 you can get a very nice balance that will find multiple uses in your home and hobby. Use fresh, Distilled or RO water. One decimal place rounded based on two decimals of precision is all that is needed.

Bean, Thanks for the explanation on bubbles. You are correct on the second draw there are significant less bubbles.

 

[BeanAnimal]

Lasse thank you. Can you explain why you would need adjust the display measurement? Isn't the whole idea to trust the GHL KD Director?

going to take a stab here - the results could differ from system to system based on many factors from callibration error to interference to actual water chemistry and temperature compensation. In the end stability of readings (precision) is more important than overall accuracy. That way if you see a .3 or 2 (or whatever dKH) swing, you know it really is a .3 or 2 (or whatever) swing... be it .9 or .2 off of another repeatable (precision) device.

 

[BeanAnimal]

If you do 10 back to back readings and they are all over the map, something is certainly wrong. You do a reading later that evening or the next day, how do you know what is real or not?

If you do 10 back to back readings are they are all within .1 (or whatever) they you are better off. You take a reading later that day or the next (or whatever) you can be assured that the difference between the 2 readings is real.

 

[Lasse]

Lasse thank you. Can you explain why you would need adjust the display measurement? Isn't the whole idea to trust the GHL KD Director?

Its a question of references. If I´m used to judge my aquarium health with KH measurements with on method (The figurers could be wrong but experiences say to me that if this method show 7 - all good) I change my method and this new method can give a more true or false number - I do not know. But I know that with my old method 7 was good - let us than tweak in the new method to show the same - and I can use all of my references. I use my KH director as a day to day tool - but now and than - I dubble check with both Hanna and a drop test.

Sincerely Lasse

 

[Kenny311]

Lasse well stated! Thanks for all the help. I going to go with the GHL readings. I've set my GHL dosing pumps to respond to KH Directors readings. Let's see what 7 days worth of dosing control via KH director does. I'll do a Hanna & Red Sea test next week and see what my levels are at. Thank you to all that assisted. This community if fantastic!

 

[Kenny311]

If you do 10 back to back readings and they are all over the map, something is certainly wrong. You do a reading later that evening or the next day, how do you know what is real or not?

If you do 10 back to back readings are they are all within .1 (or whatever) they you are better off. You take a reading later that day or the next (or whatever) you can be assured that the difference between the 2 readings is real.

@BeanAnimal thanks for the input. I see your point and agree. Im not going to focus on the number but instead I'll track the variance. Ill report back next week. Thank you again!