How To Make 4 kH Solution for Co2 Drop Checker

[Jag1980]

I tried this twice with the same results each time.

2oz. (60ml) of Distiled Water
Baking Soda
kH Test Kit


A Bowl of Distiled Water Ready for Mixing

Touch the Tip of your Little Finger on the Surface of the Baking Soda just enough to get a Little Bit to Stick like shown in Picture:

Dip your Baking Soda Finger in the Water and Stir until Dissolved:

Test your Water with kH Solution and it Should Read a kH of 4:

Use 5ml of kH4 water and add 3 drops of pH solution and you have your Drop Checker Mixture Correct?

 

[Fishy_Fun]

Its a little harder than that.I just kept testing and if the kh was higher than four i would add water and if it was lower i would add some baking soda.It was a lot harder to do mine since i used tap and bottled water.Most people will say its inaccurate since you don't know the moisture content of the baking, which is true but it has worked for me.

 

[Jag1980]

What pH should 4 kH water solution be?
pH 7.0?

 

[Fishy_Fun]

Yes it should be neutral for easiest testing

 

[Sploke]

glad to see we're using precise measurements here...


http://www.aquaticforest.com/guides/how-to-make-a-4dkh-solution/

 

[James0816]

I have the benefit of a lab and a great chemist. ;o)

He threw the distilled water out that I brought in and used his "ultra pure" water. Then using a mega sensitive scale (can't remember the name of it but it will actually measure the weight of a grain of baking soda) got the exact measurement needed.

Presto....1 gallon of 4dkh

 

[The Zigman]

I just buy it for $2...
saves me tha hassle, and frees up time to drink beer...

 

[Squawkbert]

I have the benefit of a lab and a great chemist. ;o)

He threw the distilled water out that I brought in and used his "ultra pure" water. Then using a mega sensitive scale (can't remember the name of it but it will actually measure the weight of a grain of baking soda) got the exact measurement needed.

Presto....1 gallon of 4dkh

That's more or less what I do - Karl Fischer moisture determination on some baking soda, then add correct amount (weighed to several decimal places) to some ultrapure Milli-Q TOC sourced water.

 

[Jag1980]

Well I don't have access to a lab or a precise digital scale. I don't want to pay a bunch ordering from online, since everything online cost shipping, $8+ for water? then you have to wait a week. I got a drop checker kit from the store, just made a batch of Co2 and no way of getting 4 kH solution now, not a week later. I didn't want to use up a whole gallon of water to make 5ml of 4kH water, So I tried this... I took a picture so anyone can see a idea of about how much you will need to mess with to get 4kH if you ever need to make some...
The accuracy of this 4kH solution is probably as accurate as the drop checker and all our other water testing chemicals, it's not 100% perfect.

 

[Riiz]

What pH should 4 kH water solution be?
pH 7.0?

It should be a deep blue, lol. If its green to begin with, how its going to let you know when you hit 30ppm or so of CO2.