I use a 1:1 ratio of soap:washing soda (no borax). The soap I make also has a -2% superfat, and I use vinegar in its production to get 3% sodium acetate (I feel this makes it a little more crumbly and easier to grind; more info about using it here).
The citric acid comes into play for me during the rinse cycle, where I use a 10% citric acid solution in place of fabric softener.
Ok, great! and how much of it do you use per load?