I would suggest you mix the kalk in a gallon jug, 2/3 gallon of RO water, 1 tsp Kalk powder. Shake it up reall good and then let it sit until the water clears. Fill your doser with only the clear liquid, not the sediment on the bottom, nor the scum film on the surface. After you do it a few times you'll probably get a better feel for it.