The equilibrium between calcium and carbonic acid is often disturbed in marine tanks due to biological activity. This results in a shortness of calcium and an increase in pH. Calcium Reactors help create a natural calcium-carbonate, which is virtually insoluble in alkaline water. Carbonic acid is injected into the reactor to produce a lower pH in the chamber and start calcium hydrogen carbonate going into solution. This method of adding calcium will not effect pH like the use of "Kalkwasser". Use with a CO2 system and pH controller to achieve ideal water chemistry.