Salty Q&A: Calcium and Alkalinity Out of Whack

Maintaining stable parameters in the accepted range is much better than chasing “ideal” numbersQuestionI’m having an issue with the calcium and alkalinity levels in my reef tank. Right now, the calcium is at 380ppm, which is at the low end of the acceptable range, and the alkalinity is at 10dKH, closer to the high end of the acceptable range. I’d like to get the calcium up over 400ppm so I have a greater margin for error. But whenever I add more calcium supplement than usual, I notice that the alkalinity level drops afterward. Any idea why this is happening? Is it coincidence or cause-and-effect?” – Submitted by Ross C. Answer Thanks for your question, Ross