KHG DIY or Alternative Reagent

Randy Holmes-Farley · Jun 2, 2019

ihavecrabs said:
I feel that would throw the accuracy of the test off given it is programmed to a specific acidity of titrant. My brain is working on half cylinders at the moment so sleep and then coffee might help me make more sense of this. Maybe not though!

Alkalinity titration results are not generally dependent on acid titrant concentrations, unless it is very weak. Obviously, though, the interpretation needs to know the concentration for calculations.

Randy Holmes-Farley · Jun 2, 2019

jjoos99 said:
within the system setup there is a line to adjust kh. So what I did was run a test with the guardian and a test with my hanna checker. If the guardian is .5 lower then the hanna you enter +.5 into the adjust kh line and save the settings. The next test will be dead on with the hanna readings. Reading the manual it warns against using any diy reagent that might damage the components in the mixing chamber. I dont know for sure but from what I have read the tests use an acid based reagent to measure the ph change within the chamber after each drop so I have to wonder how this diy method would be any different. When I cut open my oem guardian reagent some of it got on my scissors and stained them pretty bad so it must be fairly strong stuff. I guess the worst case would be I have to replace the mixing chamber and possibly the ph probe. worth the gamble.
Jeff

Unless you are changing the titrant concentration, I would not assume the Hanna is as, or more accurate than, a true pH titration.

ihavecrabs · Jun 2, 2019

Randy Holmes-Farley said:
Alkalinity titration results are not generally dependent on acid titrant concentrations, unless it is very weak. Obviously, though, the interpretation needs to know the concentration for calculations.

What I was attempting to say, much more eloquently said.

Essentially in order to get the khg to read properly, we need to either replicate it st thr exact concentration or reprogram it to a new concentration.

ihavecrabs · Jun 2, 2019

@Randy Holmes-Farley

Is there a best practice way to determine the concentration of a acid?

Randy Holmes-Farley · Jun 2, 2019

ihavecrabs said:
@Randy Holmes-Farley

Is there a best practice way to determine the concentration of a acid?

Yes, pH titration with a standard base. Like 0.1 n NaOH. Make it, or best, buy the standard.

Randy Holmes-Farley · Jun 2, 2019

ihavecrabs said:
What I was attempting to say, much more eloquently said.

Essentially in order to get the khg to read properly, we need to either replicate it st thr exact concentration or reprogram it to a new concentration.

Yes, that makes sense.

coralbeauties · Jun 2, 2019

Randy Holmes-Farley said:
Yes, pH titration with a standard base. Like 0.1 n NaOH. Make it, or best, buy the standard.

I am totally dumb about the chemistry and how to perform it but I know that the diy reagent is resulting in near identical readings to both my salifert and hanna tests. It has been pretty much rock solid in the tests.
Jeff

ihavecrabs · Jun 3, 2019

Randy Holmes-Farley said:
Yes, pH titration with a standard base. Like 0.1 n NaOH. Make it, or best, buy the standard.

I'd also like more details on pH titration to figure out what standard might be used or customized.

Is there a paper you recommend that won't go too far over my head??

yellojello · Jun 3, 2019

Im going to try to follow this guy’s post taken from the WAMAS forum:

https://wamas.org/forums/topic/84376-kh-alkalinity-monitor-with-aim/?do=findComment&comment=733500

ihavecrabs · Jun 4, 2019

yellojello said:
Im going to try to follow this guy’s post taken from the WAMAS forum:

https://wamas.org/forums/topic/84376-kh-alkalinity-monitor-with-aim/?do=findComment&comment=733500

Yes! This is exactly what I was looking for. You rock!

ihavecrabs · Jun 4, 2019

@gws3 Thanks for your write up on WAMAS in regards to DIY reagent. I'm sure I speak for everyone here when I say that we'd be interested in learning more as you have been using this new reagent for a year or so at this point.

gws3 · Jun 4, 2019

ihavecrabs said:
@gws3 Thanks for your write up on WAMAS in regards to DIY reagent. I'm sure I speak for everyone here when I say that we'd be interested in learning more as you have been using this new reagent for a year or so at this point.

Yes, I have been using my own HCl reagent for over a year. I'm using either the .0227N or .0244N concentration, can't remember which off the top of my head. I have had no issues using DIY reagent. The cost is less than 1% of the manufacturer's reagent. I did not previously post my findings on R2R out of respect for the manufacturer, I'm sure the money they make selling reagent helps pay for all the R&D they did to develop the product.

As for the KHG itself, they are excellent but require significant maintenance and troubleshooting, especially when running tests hourly like I have been. Definitely better for the technically minded folks that are willing to work with them to get them producing consistent test results. I've been running mine for over a year now at a test an hour, so I'm probably around 10,000 tests on each unit. So if I look at it that way it is no surprise certain components are getting worn and require replacement. I may reduce the testing to every 2 hours to double part life expectancy. Replacement parts are relatively cheap, and the folks at Dr. Bridge offer excellent customer service.

ReeferBud · Jul 25, 2019

yellojello said:
Im going to try to follow this guy’s post taken from the WAMAS forum:

https://wamas.org/forums/topic/84376-kh-alkalinity-monitor-with-aim/?do=findComment&comment=733500

Does this also work for the Alkatronic?

ihavecrabs · Jul 27, 2019

ReeferBud said:
Does this also work for the Alkatronic?

In my search for KHG reagent I stumbled on a few Alktronic and it seemed that it may use the 1N strength acid, but you should definitely research it as I didn’t pay much attention.

That said, this solution would not work if that is the case.

ReeferBud · Jul 28, 2019

Thanks. I haven’t found anything so far on Alkatronic DIY reagent. Will continue searching but if anyone finds something, please post it here!

gws3 · Jul 29, 2019

ReeferBud said:
Thanks. I haven’t found anything so far on Alkatronic DIY reagent. Will continue searching but if anyone finds something, please post it here!

If the alkatronic is using a pH probe this method should work. It most likely uses hydrochloric acid or sulfuric acid as reagent. Which one doesn't matter, you just have to determine a comparable concentration. Determine the volume of the baseline reagent required to drop a test sample to a pH of 4.5. Then determing the volume of the suggested 1N HCL reagent required to do the same. Then dilute the HCL as required based on the ratio of the volumes. This will yield a comparable reagent.

traxxonwaxx99 · Mar 9, 2020

gws3 said:
Yes, I have been using my own HCl reagent for over a year. I'm using either the .0227N or .0244N concentration, can't remember which off the top of my head. I have had no issues using DIY reagent. The cost is less than 1% of the manufacturer's reagent. I did not previously post my findings on R2R out of respect for the manufacturer, I'm sure the money they make selling reagent helps pay for all the R&D they did to develop the product.

As for the KHG itself, they are excellent but require significant maintenance and troubleshooting, especially when running tests hourly like I have been. Definitely better for the technically minded folks that are willing to work with them to get them producing consistent test results. I've been running mine for over a year now at a test an hour, so I'm probably around 10,000 tests on each unit. So if I look at it that way it is no surprise certain components are getting worn and require replacement. I may reduce the testing to every 2 hours to double part life expectancy. Replacement parts are relatively cheap, and the folks at Dr. Bridge offer excellent customer service.

Hi I know this thread is a little old but since KHG is really basically going to be discontinued, would like to see if there was a final consensus on how to DIY our own reagent. I have Hydrochloric Acid 31%, do we know the exact amount to mix with 1500g of distilled H20? Thanks!

coralbeauties · Mar 9, 2020

I make mine up with 5.5 ml of acid. Then let it run for a day so that I know it is using the new reagent. Then test with a Hanna meter or your text kit and adjust the settings in the guardians program to match your test sample. I readjust the setting with each new bottle that I use. I get some goofy readings every now and then but can’t blame that on the reagent.
jeff

Cliff717 · Mar 9, 2020

Why would khg be dis-continued?

traxxonwaxx99 said:
Hi I know this thread is a little old but since KHG is really basically going to be discontinued, would like to see if there was a final consensus on how to DIY our own reagent. I have Hydrochloric Acid 31%, do we know the exact amount to mix with 1500g of distilled H20? Thanks!

traxxonwaxx99 · Mar 10, 2020

What’s the purity of the HCl you are using?

jjoos99 said:
I make mine up with 5.5 ml of acid. Then let it run for a day so that I know it is using the new reagent. Then test with a Hanna meter or your text kit and adjust the settings in the guardians program to match your test sample. I readjust the setting with each new bottle that I use. I get some goofy readings every now and then but can’t blame that on the reagent.
jeff