Quote Originally Posted by gainer View Post
Washing soda is sodium carbonate with a bunch of water of crystallization. Calcium carbonate is limestone which would probably work as filler to take up airspace in a developer bottle, or to pave your driveway. Just a slip of the periodic table, I expect.
Sorry, I forgot exactly what it was. I knew it wasn't Bicarbonate so I was concentrating too much on not typing that.