7 weeks into flower - Issues after a feed

The dried brow tips curled up and in is nutrition burn. You had that for a bit. When leave roll it is likely to hot. I would say its 2 issues going on. 1 the ph in soil is off or crossing the safe line range. Causing lockout and nutrition issues. This is caused by too much nutrition in soil causing the burn a lot of times, Not having a good run off each watering can cause this. Plus can test soil ph from run off. 2 possibly too warm. Good luck and happy growing 🌲🌲🌲👊

Excess potassium can give the same look as the calcium deficiency too. Rusty spots, curling, etc. Id definitely say check the ph accuracy, see what your runoff ph/ec are and go from there. If you did overdose on any nutrients, then flush them with some plain ph'd water and bring it in a little lighter in the next watering. ✌️

It looks like it's been building over time. Not just a sudden nutrient burn. Sometimes if the lights are too close they'll cause a burnt and crispy look like that, even without the room temp being too high. The spotted look always makes me first think of a calcium deficiency...are you giving any calmag or is your ph off? Possibly recalibrate your ph pen if you're giving all the right nutrients. I had some plants show some very drastic leaf problems that all ended up being from the ph being inaccurate because of my ph pen(spotting, curling, clawing, burnt tips etc). I don't think your harvest will be ruined but this might take your yields down a bit.

Start off by checking ph. It’s either excess or lack of potassium