Noobie question

So i've been running a 10 gal dwc with 400w MH for veg, and 400w HPS for flower, however for the passed few weeks i had changed it back to MH to test out some theories that i've read about regarding MH giving denser and tastier buds and what not. My question though.. i'm VERY late into flower, I'm pretty much just waiting on trychomes to begin to turn (not sure which week. amateur mistake i know). Is it normal for pretty much every leaf on the plant, fan leaves and sugar leaves around the buds to dry up and pretty much die? It seemed like it happened overnight, i lose track of time so probably over one or two days. I think this may be a sign that i'm nearing the end of my grow, but this is my first time, so i'm not totally sure.. i have a feeling this may be normal. any input is appreciated

They pretty much fall apart when they're done, so you shouldn't worry.
It's actually quite impressive that you haven't done the usual first grow mistake and cut her too early (I'm guilty of that, as are 90% of us here )

Pics?

Here are some pictures. all of these leaves are almost crispy dry. I have already cut off majority of the dead fan and sugar leaves and plan to use them for some BHO. Imgs 1-5 don't do her much justice as they're taken with an iPhone 5, however Img6 is taken with an iPhone 6 a couple days before the leaves dried up and has a better picture.

You will notice that after a few weeks at 12/12 your lower fan leaves will start to turn yellow and die off. Wait until those leaves are more than 50% dead before removing them. Photosynthesis is the process where the plant turns light energy into a form the plant can use. And that process is performed by small organelles on the underside of fan leaves. So it is important to keep the fans as long as possible.

Good luck, BigSteve.