Harvest question

So it has been 7 1/2 weeks since I switched over to 12 12 in my first grow in soil with ff nutes. The buds have started to frost a little and the hairs are starting to turn amber (I would say maybe 15-20 percent of the hairs have started to turn) and they buds are really starting to look like buds. I was planning on harvesting either 10 days from now or 17 days from now. I was going to try just water for the last week (no nutes) and 36 hours of darkness before hanging them up. My question is: A lot of the fan leaves on all 4 plants are starting to turn yellow in the last few days (mostly from the bottom up). A hand full of them were "dead" enough to just pull off and I've cut a few others off. I'm assuming I either have a deficiency that is now developing or that the leaves are dying as part of the plants end of life cycle. Not sure which, but as they are almost done I feel I'm kind of too late in the game to diagnose a deficiency and if I pick them asap (next week after week of water) I would still have a decent harvest. I would like to give them the extra week of lights to get more frosty and developed, but with dying leaves I'm wondering if I should maybe pick early. So my question is this: They are due for their last feeding tomorrow before week of just water. Should I skip final 8 week feeding and let them start their final week of just water a week earlier. Final plant age will be about 4 months to the day, with 12/12 switch to harvest at about 8 weeks and a few days if I stay on schedule, 7 weeks and a few days if I cut it shorter. I guess what I'm asking specifically is will the plant still continue to develop effectively with yellowing and dying fan leaves for aprox 10 more days under lights or is it better to just call it and start the harvesting process?

Thanks for any help in advance.
Poppi

Don't worry about those fan leaves this late in flowering...if they die and you can pull them off then go ahead and pull them off...its normal for fan leaves that don't get much light to die off, also the plant will suck nutrients out of the leaves towards the end so you'll see deficiencies in places. Do not harvest now, give it as long as you can and watch how swollen your calyxes get, and if you have a magnifier look at your trichs to see if they are all cloudy with just a pinch of amber...basically a combination of the majority of your pistils going brown, cloudy trichs, and swollen calyxes tell you when to harvest

Good advise. I'll wait Thanks.