DIY KH Keeper reagent

e34stx · Dec 28, 2021

Hi everyone, i see there are a lot of diy's for alkatronic, kh guardian etc but none for the kh keeper. has anyone successfully created a homemade reagent with HCL?

e34stx · Dec 29, 2021

anyone?

Dennis Cartier · Jan 1, 2022

I had never heard of the unit until you asked about it in the DIY Alkatronic reagent thread. Looking at it, it uses a 9:1 mixing ratio for the reagent. Do you know how much aquarium water is used per test?

I am sure we can calculate/guesstimate the strength of the reagent and come up with an over the counter replacement. It might take some trial and error, but it should be quite feasible to figure it out.

Dennis

Dennis Cartier · Jan 1, 2022

I thought about this some more. Do you have a Salifert alkalinity test on hand? If so, can you do a test using 1 ml of the mixed reagent from the KH Keeper. Let me know what the reading on the syringe is after the colour change occurs. Also please let me know what the actual tested alkalinity is (using the tests reagent).

Dennis

e34stx · Jan 1, 2022

Hi I only have the red sea pro dkh..and thanks for the reply I will have a look and get back to you.

e34stx · Jan 1, 2022

I tried the rs test kit and it didn’t work even diluted with 9 parts ro.

Dennis Cartier · Jan 1, 2022

e34stx said:
I tried the rs test kit and it didn’t work even diluted with 9 parts ro.

Unfortunately I only have Salifert, so I am not sure how the Red Sea one works. If you can get a hold of the Salifert version and use it to test, we should have a shot at figuring out what the normalization of the KH Keeper reagent is.

Dennis

e34stx · Jan 2, 2022

ok thanks i will try and get one,

elysics · Jan 2, 2022

Iirc, the kh keeper reagent is 0.2N concentrate that is then diluted to 0.02N. Only looked at it by the numbers though when reverse engineering how the thing works, didn't actually try generic acid it out on an actual unit

Dennis Cartier · Jan 2, 2022

elysics said:
Iirc, the kh keeper reagent is 0.2N concentrate that is then diluted to 0.02N. Only looked at it by the numbers though when reverse engineering how the thing works, didn't actually try generic acid it out on an actual unit

Hmm, interesting. That is the exact (diluted) normalization as the Alkatronic. They start with 0.1N and dilute it 4:1 to end up with 0.02N as well.

This can be confirmed by the Salifert test using the KH Keeper reagent. The formula for converting the Alkatronic result when using the Salifert test with it's reagent is:

( 1-syringe reading ) x 250 x 0.056 = dKH

If the KH Keeper is also 0.02N after dilution, then that formula should also work for the KH Keeper.

Dennis

e34stx · Jan 2, 2022

i Have some 0.1n Hcl so I may dilute 4 parts ro to 1 part Hcl and give it a go

Dennis Cartier · Jan 2, 2022

e34stx said:
i Have some 0.1n Hcl so I may dilute 4 parts ro to 1 part Hcl and give it a go

That sounds like a decent idea.

Dennis

Borat · Jan 2, 2022

To run a titration test (any device) using 0.1N hydrochloric acid in a 100ml volume of test water you need approximately 3ml of reagent (at DKH 8.4)..

If you can track the amount of water and the amount of acid being added (is that info not provided on the app??) - you can calculate the rough concentration of acid.

Dennis Cartier · Jan 2, 2022

Hmm, well they show the device using 7ml of reagent for 8.0 dKH in their advertising, but I am not sure what the volume of water they are testing is.

Perhaps the test with 0.1N HCL diluted down to 0.02N will bear fruit.

Dennis

elysics · Jan 2, 2022

Dennis Cartier said:
Hmm, well they show the device using 7ml of reagent for 8.0 dKH in their advertising, but I am not sure what the volume of water they are testing is.

Perhaps the test with 0.1N HCL diluted down to 0.02N will bear fruit.

Dennis

7.15 to be exact, and that is in 50ml, should be 0.02N yes

Dennis Cartier · Jan 2, 2022

Borat said:
To run a titration test (any device) using 0.1N hydrochloric acid in a 100ml volume of test water you need approximately 3ml of reagent (at DKH 8.4)..

If you can track the amount of water and the amount of acid being added (is that info not provided on the app??) - you can calculate the rough concentration of acid.

elysics said:
7.15 to be exact, and that is in 50ml, should be 0.02N yes

Both of these sync up nicely with the quantity of reagent they advertise as being needed for 8.0 dKH.

For @Borat 's example (converted to 8.0 dKH, using 0.02N and 50ml sample size):

(8/8.4) * 3 * 5 / 2 = 7.142857143 ml

Which matches what @elysics calculated it at (7.15ml).

Now let's see if it works for @e34stx using his 0.1N HCL on hand.

Dennis