Wow...sounds good. temps you want to try and get into low 70's in flower. It looks like toxic salt build-up???despite all the measures you took...I am kind of stumped. Heat can also contribute to those problems...what is humidity in closet?
best thing I can advise is flush completely.

perhaps you can get them back on track, but from the looks of them, the damage is done. I would consider flushing and taking the most damaged plants and harvesting them. leave the healthy one/s to finish. I use the exact system (partially, I have so many different systems)(right now I am vegging in this type of drip system and transfer to bubblers for flowering)
and you shouldn't have any problems with this. Anyway goodluck and let me know what you decide to do>>>When you start again...we will go from scratch. peace
latewood Reviewed by latewood on . I think shes dying Well outa 4 only one is showing signs of nute burn... there alll bag seed, now i increased my nutes a couple days ago from 800 to 1000 and the 3 took off but the one has leaves that are curling down and in like a canoe, i have about a week left of flowering before there done, im gonna cut nutes in about 6 days and feed em plain water for a couple days. this is wack Rating: 5