Can use your advice. Deficiency?

[PhatNug]

Thanks for even clicking here to help me sort this out.
So here is the run down.........
kush plants
12x12 internal grow room
4 weeks veg state
650 led Blue/Red
Temp in 70's
Hum 40%-50%
Running nutes are 24 8 16
Soil is MC .21 .07 .14
18/6 light ratio

There are hese little dry white crystals that are forming in the dry areas. You can see it on the second image.
Thanks

 

[PhatNug]

Aaarrrrgggghhhh!

 

[PhatNug]

 

[PhatNug]

 

[groover]

It looks like something has been havin a feed on ya plants mate.
Get some moth balls and sticky traps in there mate.
Looks like a bit o nute burn too i think(give em a flush).
The last pic (the crunchy lookin one) looks like my mates plant
and he has a severe root rot problem(i'm noy saying tats wot u got but).
How are ya roots lookin mate. If they are a bit on the brown side u will need
to get those plants medicated(there are a few different products Oxyplus by
GT is good i've been told).Hope you get on top of it. Check out the abuse chart below.

https://www.420magazine.com/community/threads/plant-abuse-chart.71664/