With this tank for the fist two years all I did was mix Kalk in a jug of water and pour it directly into the wet/dry. CRAZY!! I know. Called a Kalk Slurry. Now I mix the Kalk in gallon containers and by adjusting with a small valve slowly drip into the filter. One tsp per gallon NOT eliminating the excess settled kalk from the bottom. I used to start fresh every time by rinsing the containers out because everything I read said not to add the settled portion, but haven't done that for over 6 months and have notice NO difference in water quality. My old tank had a bunch of fancy do-dads, big skimmer, Calcium Reactor, Chiller, ATO, Electronic this and that etc.. I'm avoiding that with this one. I went simple and love it...