That's basically the same as dripping, meaning you're adding small amounts at a time. What you're doing with KW is fine, except for the fact that running KW through the osmolator pump will supposedly shorten it's life span and voids the warranty. Those pumps are only $20 or so, so lots of people do it and just plan on replacing the pump more often. Two teaspoons of kalk/gallon is saturation. For a long time, there was an assumption that leaving the KW open to the air resulted in it losing strength quickly as the KW interacted with air. It is true that KW in an open container will drop in ph quickly, but Randy Holmes-Farley wrote an article demonstrating that since the KW does not lose conductivity, it must be remaining full strength, and consequently delivering the same amount of calcium and hydroxide ions to your tank. The hydroxide ions combine with dissolved CO2 in the tank water producing carbonate ions.

There still is some controversy regarding the ph effects of KW from a reactor vs an open container. KW exiting a reactor has a ph of 12.2-12.4, if the reactor is working correctly. I have verified this with my own KW reactor. If you were to measure the ph of the KW in your reservoire several days after adding the kalk powder, you would find that the ph will have dropped substantially. I'm not sure how this affects overall tank ph, as the tank ph is based entirely on the level of dissolved CO2 in the water.