Leaves are yellow and tips are dying

Week 5 of flower. The leaves are turning yellow and the tips are dying. Most of the lower leaves have already died and fell off. Im pretty sure it's a deficiency (or two). of some sort. I have only fed her a couple of times. Because she has always looked good.until recently. Here is a pic. I know it's under my HPS but if I turn it off it is dark. You can see the tips well though. The very top leaves are curling lengthwise as well. The top part of the plant is still green. Thank you very much for any insight you may have.
http://i745.photobucket.com/albums/xx93/91GT347/image28_zpspcy9qx6k.jpg

Feed the poor girl.

Yeah, i kind of figured that. I'm sure there's very little or no N left. Should I go with bloom or veg. or a combo ?

Depends on which nutes you're using. Some bloom nutes have lil to no nitrogen. If yours has nitrogen i'd use the bloom, if not I'd give a reduced dose of veg nutes.

Bloom nutrients often exclude nitrogen because as the plant gets closer to flower, it no longer needs as much nitrogen for vigorous growth. Yellowing is normal during these phases. That being said, a small bit of nitrogen can be helpful in greening up a yellow plant.
Not all growers add late doses of nitrogen, and they prefer it that way.
Does your grow journal show a history of underfeeding?

Yeah, they always start turning during flower. This is quite a bit earlier than usual though. Under normal circumstances I know, at least for the most part what is going on. I ran into this problem, because I acquired this one and it was to the "HAVE to be transplanted now" stage. He brought it to me, and I was not expecting it. So I had to get some soil from a pot my dad had a tomato growing in last year. Which I know was a little bit of Miracle grow soil mixed with something Scotts brand. Pretty sure it was top soil. I had no idea what he had put in there. So I gave it a light feeding about 2 weeks later. Then another when I switched the lights to 12/12. It had been sitting outside for almost a year, in the rain(We had a lot). I figured most of the nutes had been flushed out by then, but wasn't sure. I wondered about adding some Nitrogen Since it probably doesn't have any. I know it doesn't need much now, but it does need a little, right ? I was thinking maybe use the bloom, and add something that is N only, at about 1/8 to 1/4 strength. Good idea, or no ? I hate to sound like a noob, but I really have never ran into many issues like this. Good media, nutes, and a plan seem to keep this from happening. lol Thank you for your input