I use the Aspirator system pictured above to drip Kalkwasser into my reef tank overnight. The Aspirator holds about five litres of RO water. I then add about 1 table spoon of Kalkwasser powder and shake for about a minute to mix. I then leave for a couple of hours to let the un-dissolved powder settle onto the bottom of the aspirator. This then leaves a clear calcium hydroxide solution which I then drip into my aquarium slowly overnight.