You should not stir it if it is in the ATO - the powder that's not in dilution should be in the bottom. I used two containers and let the powder set at least on day before using it - and of cause - the inlet for the ATO pump must be at least around 2" above the bottom.Never again will I use kalk in an ATO for all the reasons mentioned above and the dummy ideas I get to increase the kalk going into the display through the ATO.
Sincerely Lasse