Kalkwasser reactors such as the IceCap Kalk Mixing Reactors and the Two Little Fishies KW Reactor are the most efficient way to use kalkwasser. They can be used in conjunction with either a dosing pump or an auto top off. These reactors constantly stir kalk powder into water making sure that the water exiting the reactor has the maximum amount of kalk powder dissolved in it. Kalk reactors also reduce the maintenance associated with the other methods as kalk powder only needs to be added every few months. Useful Articles: Kalkwasser Overview.