I haven't been having any trouble with my water chemistry, until recently. In the last couple of weeks, I can't keep the TA at 70. It wants to drop. I will add baking soda to drive it up, get the pH back to 7.5, and then within a few days the TA is headed down again. It stabilizes around 30. I'm not sure why this has started to happen, or how to stop it. Thanks for any advise.