You just overfed em some man.
Get some water pH'd, if you can and pour it in there and get that high salts water off that root zone so the plant can grow some more root hairs.
Get yourself a $9.99 PPM pen from Amazon or wherever, and you're golden. Those plants are way burned and it's part of life growing sativas, you burn em with what seems like perfectly reasonable amounts of nutes.
Cut that back, and right now - if there's a gallon of distilled water in your house right now, go and get it, and pour it all around that plant's roots,
to get some of the high salts off that root zone so the plant can start growing more root hairs.
If you wait till you have a pen no roots are gonna grow till you flush anyway. Flush that extra salts-hot water out of there.
IF you have to use tap, pour it over the roots and don't totally, totally flush the entirety of the salts water you have in their out.
You don't want to pH shock them by taking them from firmly acidic high salts water, to neutral, with only probably one main mineral in there calcium,as well as a little magnesium and maybe, some iron.
You really need pH'd water or you're gonna probably pH shock em.
Get a gallon of distilled or filtered water, - very low ppm, and do that. It doesn't matter if it's distilled or filtered, it's effectively the same as it relates to the task at hand, dilution of intense salts concentration on the roots,
just get those high salts off that root zone, so it can start growing some more root hairs.
Don't give it full light, when it's collapsing.
If it does collapse, shade it some.
Don't beat it up ya know?
When it's collapsing, drooping, the leaves are breathing out more water than the vascular system of the plant can deliver and sunlight fuels this outrunning of the water supply so - don't give em full sunlight when they're collapsing too bad, it's not real good for em.
When they're in full light, ya know, the water they breathe out, cools em - but if they're in full light and they sorta droop over, they're running a little water short; and if there's too much depletion, the cooling reduces and the leaves overheat and it's not best.
As you get a pH pen you're gonna be able to tell a lot better what's going on.
One of the VERY best things about a Hempy is if you f*** it up, a gallon or two of purified or properly dosed water and your problems are over; reload and go again. Don't despair, AT all.
When they get burned like that and they're a little skinny leaved sativathey don't really recover real fast so get that distilled water in around those roots asap and then get a pen and start mixing some mild nutes,
Peace on yas and yes - it's worth it to go to the store or look around the house for some distilled water, spend that two bucks, get the gallon water, and pour it into the plant's root zone right now.
At least, in the opinion of my therapist who I consult and consider responsible for anything I say.