:smoking: and learn well you do Hemi'!
... it's often overlooked, but the plants can
tolerate a wide range of sub-optimal conditions, nutes, etc.,... it's just that we are trying to push the plants some (or a lot), and provide what they need to do this and make good yield and quality,... consider what they experience outside, which is where I grow mostly,... I cite
@912GreenSkell as a adverse conditions grower of serious note here! He's in Canada, where any time, any place shite weather can happen,... wild swings in T, RH%, storms,... I marvel at what he produces, but it's a great case-in-point about tolerance,... Also, large plants definitely have a "mass effect" stability that tent grows can only dream of too,...
... anyway, the whole point of the VPD thing is it's a factor in your troubles, as it is in many others,.. it's been a great dot-connector for me in Sick Bay, when diagnosis is difficult and at times contrary
.... How are they looking mate, were you able to make some corrections, and has progression slowed at least?
>>
@Nosias 
... for hydro, which I haven't done, I'd direct you to others who are more savvy than I! Sure, I know
some stuff, out of sheer necessity in diagnostics, like for coco as well,... res' T is a biggie, upper 60's low 70's I think,... One thing i do see more and more of is light-caused stresses, not necessarily burning, but overload on the photon level, not so much outright T (like you get with HID),.. it can have a proximity effect, not hitting the whole plant like a pH lockout for example, but just those tops/ areas closest to it,... overdrive the PS machinery, and it breaks down basically,... any bad combinations of high light/heat, very low/high RH%, overly strong air movement, can cause transpiration stress,... if you want to learn more about VPD, check out the reference section in the Infirmary sticky section,...
>>>
brudda
Playah! Word, on all that-
... I harp and I carp, and still, even some of my besties here, all better growers than me, still run into hiccups form time to time,... two of my fav's Rebel and Sniper are devout pH-thiests
... they don't test doodly, and somehow get away with it most of the time,... then once in a while the shit-show tickets are issued, and I always ask " WTF is the pH?!"
hsoil:
I only have one last question though. Does anyone have the conversion factor for translating "shitloads" to "shit-ton's"??? I hate those metric to SAE conversions....
let's ask
Don Skelly 
-- he works with large quantities!
... yes and no IMO, that's why I echoed "guideline" like some of the authors did-
,... Air movement, and a host of other things that can fudge things some,.. but I don't think that 2C chart is at all wrong for general T & RH% during bloom, during light hours (!- not at night, though transpiration is much slowed then); that yellow zone looks OK to me, barring something like a landrace Hashplant or something that notorious for weak mold resistance,..
(check out those sweet Pulse Nano units here, very cherry!)..... I don't know where to even find the other charts for leaf surface temps 3+ degrees cooler than ambient- 
wacky weather makes for some knuckle chewing worries no doubt! One can see why the high end grow gear with remote controls can be of big help when this is happening,.... * cough $$$ cough* 
Meantime, getting that T down and the RH up is bottom line fix for sure, or all you'll do is chase your tail on this fixing symptoms shit and not the fixing potential the root cause,... you'll see some charts at that link, it's a bit confusing until you read the article and see the vid, then you'll get the gist of how once you're out of that proper VPD zone, things can start to go sideways,... reading the more complex charts is bit of a PITA, and not knowing the actual leaf surface temp is a big factor (there 1 and 2 degree C tables there, I'd use the 2C as a guideline), but the bigger picture is there, not so much the minutia,....
So you learned more faster, good job!!!
