| | Re: 4Dkh from Ph4?
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