I have followed a introduction how to make 4dkh with smaller amount of distilled water and baking soda.
i got to 150ml of distilled water and tiny bit of bi-carb soda(baking soda). I have api and Hagen kh/gh test. Both confirm 4 drop turn yellow (4dkh).
But when i pour into my glass checker...
I've done a little searching around on how to do this but the videos on youtube are terrible at explaining it. Is creating my own 4dKH drop checker solution as easy as:
1) Create 0-TDS RO/DI water
2) Add the right amount of seachem alkaline and acid buffer to make the solution 4dKH and 7PH