# 4Dkh from Ph4?



## paperfish (Aug 5, 2010)

Hi...

was wondering is it possible to make 4Dkh solution from Ph4 solution?

or are they one and the same?

Thanks!


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## Diana K (Dec 20, 2007)

4Dkh is water and baking soda. 
What is in a pH 4 solution?


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## paperfish (Aug 5, 2010)

Diana K said:


> 4Dkh is water and baking soda.
> What is in a pH 4 solution?


Not sure whats in it, but its used to calibrate electrodes at pH4.

I thought i had read somewhere that 4Dkh is supposed to be pH4!?.. not too sure now


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## pat w (Nov 2, 2009)

All I know is my 4Dkh solution reads in the vacinity of 7.6 pH with ambiant CO2 so it must be something else. If it's PO4 then no. The KH in a drop checker must get its hardness from carbonate or the KH/pH/CO2 chart relationships are invalid. Might as well use tank water.

Add 6g oven dried (325 deg. 1 hour) baking soda to 1000ml distilled water. = 200 Dkh water
Measure 490 ml distilled water and add 10 ml of the 200 Dkh water. = 4 Dkh water
Measure 390 ml distilled water and add 10 ml of the 200 Dkh water. = 5 Dkh water

Pat


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## Diana K (Dec 20, 2007)

Many of may tanks have KH of around 4-5 degrees, and a pH ranging though the upper 6s and low 7s. 
I do not think water with KH of 4 degrees could have a pH of 4. Not saying it is impossible, but I do not see that. 
Even my tanks that show no KH have a pH of about 6.0


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## HeyPK (Jan 23, 2004)

It is impossible. KH is measured by titrating with an acid down to a pH of 4.3 and measuring how much acid is needed.


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