I have been useing Kalk in my ato water for about 1.5 years I have a JBJ ato conected to one of those table top pond pumps it does not clog the aqua lifter I had at first would clog up after a few months and had to be taken apart and cleaned. I have been running this pump for over 1 year now with no troubles. I was useing 1 heeped table soop for 5gallons added my mag and supliments also to the ATO works fine. My sps grow slow but have a nice thick skeliton. I am fine with this method and will continue.

Bill