Bandit - Your Nitrogen def. and yellowing leaves is totally natural at that stage(late flower) and adding more Nitrogen at this point will create more leafy growth as opposed to bud growth. Your girls look very happy so let them do their thing and I promise your end result will taste much better as well. Nitrogen is believed to give plants that chemically taste people always complain of. At this stage they should only be getting P and K in large doses. Just my 2 pennies but you are doing a great job anyway so do what you do. That rom x Urk looks like a winner by the way! Peace!