The solution for a quick increase of the carbonate hardness contents / pH-buffer
The optimum value of kH is at abt. 10°kH. The kH-value reflects the pH-buffer volume of the water.
In case of a too low kH-value, there will be the danger of a pH-drop. Please do not mix in a measuring cup.
The infeed of 50ml kH+Ca 1 increases the carbonate hardness by 2°kH with 100l water.