baking powder - soda equivilent, plus?
 

I have been making my own baking powder for years.

1 part soda
2 parts each cream of tartar and arrowroot (can't have cornstarch)

Some of my "bread" and "cake" recipes call for a tablespoon or more of baking powder, which I'm sure adds unwanted carbs.

I want to start using only soda, but am not sure what I should add to it to get the same rising power. I am assuming that the powders add an acid to the soda, which causes the bubling action. Am I right?

So if I use just soda, what would I add for the acid? Vinegar? Or would something else. Or are the nut flours acidic enough?

Paleo recipes most often have honey in them, and I guess it adds the acid.

Please advise.

I know little of baking chemistry, but soda and vinegar are in a lot of recipes I've made and it works well. I hope someone else comes along with more knowledge.