Cab: Fermaid K Yeast Nutrient

I remember reading that more yeast nutrient should be added midway through fermentation - after re-looking it up, you add another dose after 1/3 sugar depletion. We're using FermaidK, which to my surprise includes DAP. Added today (although sugar 1/2 depleted, so added a bit less than recommended dose). Fermentation is looking and smelling great so far!