Mysterious problem

[DarrenAdam420]

Heys guys, i have 3 plants (all details bellow) and i did not feed them until yesterday and 2 of them they look pretty yellowish as expected but the other one just looks weird, she became darker than the others and then she became like this:

The leaves have a very harsh / dried texture and also light and brown spots on them but the lower growth looks better (2nd picture)

Strain - Auto Northern Lights
# of Plants - 3
Grow Type - Soil
Grow Stage - 1st week of flower
Bucket Size - 4L
Lights - (1) 55 Watt LED
Nutrients - Green House Feedings
Medium - Supermarket soil
PPM - 600
PH - 6.5
RH - 50% to 55%
Room Temperature -24 C
Room size - 40cm x 40cm x 120cm
Pests - I looked carefully and i can't see anything anywhere

 

[TorturedSoul]

I can't see much in pictures (or real life) any more, but:

You looked on the undersides of the leaves? Often, that's where little pests roam. And some of them are quite tiny, indeed. It may be helpful to shine a strong light on the undersides of affected leaves (and those around them) from a pretty flat angle. It can sometimes bring small details to light, if you'll pardon the pun.

Also, if the older/lower growth appears to be in better shape, take a look at one of the threads on deficiencies/toxicities, with an eye towards the immobile elements. If the issue is a lack of an element, and it's an immobile one, it'll show up in the new growth first, because the element will stay in the older, healthier leaves.