I used one oz of biokleen liquid laundry detergent in my top loader with med-hard water and had no issues, clean, nice smelling diapers. About a single TBL.
Now I have a front loader and super soft water, when I had more of a full load of diapers I used 2 teaspoons at most of rockin green. Again no issues. With the tiny load I do now of nightime diapers I use a half teaspoon.