@Randy Holmes-Farley My garage tank seems to be not using or not using as much Ca. Since the beginning of October my Ca has been climbing. It was 450ppm but now its 530ppm, but my Alk is staying at 8.5. I dose 45ml of both Alk/CA. I'm using BRS's Calcium Chloride and baked baking soda. I do a 4 gallon water change on the 60gal system each week. I have to dose Ca to the new salt water mix to bring it up to 430 because its mixing below 400ppm. What would cause Ca to climb with a stable Alk? Should I stop dosing Ca to the tank until it comes back down to where I want it of 420-450 or will it go down on its own over time?