My Alk drops 1 Dkh a day. This started about a week ago. I have been having issues getting the DOS to stay primed. I was constantly getting air in the lines for BRS soda ash. I was manually dosing 3 times a day to correct it. I have now set it up with JG fittings and RODI lines. Precipitate has begun to form on the heaters, but not much. My tank has been up and running for about 9 months. The main thing consuming the Alk and Calcium is Coraline, I only have a few Montis and a couple of SPS frags. My sand is beginning to get hard and clump up. I dropped my Alk from 9 to 8 and am trying to maintain it there. It won't stay steady. My calcium stays at 420 and my magnesium is around 1380. My PH is between 8.1 - 8.3. I do not use anything to raise the PH other than the soda ash. How to I get the Alk to stay steady?