Recently, my tank has begun using up alkalinity like crazy. I've receive from BRS everything necessary for 2 part dosing, but I'm going away this week and don't want to start that till I'm back. For the last two weeks I've been using a combination of baking soda and Salifert All in One to supplement my Alk and Ca. The baking soda has been working very well for me, but do it in many small doses to avoid wild swings.