Besides the fact that the hulls seem to be tying up the N, I think they may have a bit more iron in them than the small seedlings can tolerate easily.
I've tried to do a Google search for an analysis but come up mostly with stuff for cocoa itself. But iron is always mentioned as one of the top "minerals" in chocolate. I finally found a page with something for the hulls
http://www.sunshine-garden-products....p?product_id=5
I'm not so hot converting grams and mg and such but I think that works out to about 1.4 % iron. If I'm right about that, it's a bit too high for the seedlings for me.
Whatever, it's out of my mix for now.
Carol