my blue dream plants are hurting can any one help

high everybody;new to site thanks for your time will b getting right to the point. my ladies are withering away. can anybody help identify what is going on with my plants any 411 will b helpful. few pics aviliable from 2 weeks ago don't have current pics of plants but trust me they don't look to good right now..plants are blue dream 40 of them.2 and a half months old clones..they were growing beautiful until a couple of weeks ago when they started to wilt away no more new growth.tried cal-mag but no difference just getting worse. was told its just heat stress(we have had 30+ days of 100+ degree wheather.another grower said it might be the work of broad mites?i don't know if I should just throw in the towel or keep fighting the battle?????any suggestions or info .will be appreciated thanks once again for your time;;;;;;;; peace to all..........

i would of thought magnesium an d calcium but u have ruled that out could be heat or could even be caused by confusion with lights on and off have your cycles been spot on and uninterupted?

see quite a few cupped leaves. looks like a green house. not sure where u live but most places that hot can run a Swamp coller. dont know if it will mess with ur RH but they are cheaper then A/C for that large of an area. or go buy a big ass block of dry ice throw it in a tub and vent it into the room will help them fight off the heat while dropping ur room temp.

Ohh, Blue Dream one of my personal faves... Did you change nutes?


Heat stress maybe

Are you growing outside?