plants drying up

I'm gonna go with water it more...looks dry as fuck.

If you *have been* watering it, there's not enough water retention...probably because there's simply too much coco/soil VS perlite, I'd mix more of that in.
I'd go some clay balls around the bottom as well to ensure continuity of drainage.

Looks a bit like the medium has been watered at some point but has kinf of caked up/stuck together...which means when you water again, the vast majority will go by the wayside and just leak out.
Sounds weird and counterproductive eh...put more stuff in so it drains better and that'll help it retain moisture...but honestly if you don't, whatever you're growing in tends to just turn into bricks, especially when the root system starts developing.

 

Its burnt like a mother fucker . Heat or the light is too close .
I am sorry but please disregard every thing else you have read on here .
When a plant is asking for water . Its like a girl. It nags . Not all girls to be clear only my woman .
So a plant will just hand lifeless . Limp leaves that just hang .
If it was over nuted some of the leaves would be at least dark in color over dark.
In this situation it looks as if a led is so close it burning the fuck out of them and bleaching the leaves .

 

Look at picture one . You see the very bottom growth looks ok .
The rest it gone . Again you should be feeding a veg nutrient if you are not already .
There also could be a nutrient issue . But with it all burnt i cant tell you more

 

Light Burn - Growing Exposed

 

I was pondering that, but, all the plants look the same size and are in the same area.
I'd have thought light based burns would be more uniform, and the dirt/medium does look quite packed and dry.
Either way, that's my reasoning. If it's wrong it's wrong.

 

Combination of over fertilized and dry medium locking out magnesium imo.

 

I MAY BE very well incorrect on my statement .
These plants are so far gone its about impossible to tell . If it is a lack of nutrient you think he would of posted this weeks ago lol .
Hes better off throwing them into the trash .
Lets just say we both agree he waited to long for help and there trash .