Roger,
I have the Osmolater ATO and have been experiencing low pH (7.8) and low KH (7-8 dhk). I have a 34 gal Solana tank. I believe it is due to high CO2 due to a tightly closed up house, especially this winter.
I have had several tell me that dripping kalk would help this situation. After reading your response, it seems like just the solution I have been looking for. I did not want to mix the kalk in the top off water like many recommend as I know it will eventually foul the pump.
Do you think the kalk dispenser would work. I have a few SPS, but basically a mixed tank. My calcium is running 440, so I have not had any issue with calcium, but the pH and KH have been a challenge.