Leaves on Buds drying out and turning yellow

Looking for a little advise or onsite as to why some of my buds are yellowing or drying out. Running 5 blue cheese and 4 purple Haze phenos on 3×5 closet. Under mars hydro tsl 2000 LED. Growing in organic soil with dry amendments happy frog 554 along with 284 water with well water ph'd between 6.4/6.7. 12/12 lights. Temps around 80-82 lights on & 75-78 lights out. I've never had this before. The blue cheese are the ones drying up. But not all of them. Purple Haze looks good. Oh yea it's week 8 flower. Planning on harvesting in a week as I have 25-30%amber trics. Nice to know for next run

sorry ive deleted my first post. are the buds drying or the leafs? i got a bit confused. its normal for the leafs to dry out and start dieing on that stage, looks like you are almost there

Mostly leaves. buds are rock hard.

nothing to worry about mate

Thanks I'm usually an outdoor kinda guy. Just set up this room to keep busy in winter months. Case of bad nerves I guess.