Yellowing on the margins

Hi grandmasters,

Seeing my baby below has some problems.

New growth are yellowing in the margins. Seems to be growing a bit slower than her peers.
I would think it’s light stress but my LEDs are currently 3FT above canopy and majority of the girls are without the discoloration and growing vigorously.

I did transplant from soil to coco a week and half back. Tried to remove as much soil as possible and soaked medium with mycos and that’s it. Recently started feeding.

note this condition is only seen on the smallest/weak

Hydro
EC 2.0
PH 6.0
TEMP 80
Humidity 70

Week 3 veg

So many changes
It is a miracle they are even alive

magnesium deficiency, add epsom salt to water/feed. it will stop progression and slowly recover with epsom salt in every water/feed solution

It looks to be a K deficiency, stay away from using epsom at this point it will make it worse. If it was a Mg deficiency you’d have interveinal yellowing. K deficiency has burnt tips and edges with yellowing

Problems in the root zone.

Why'd you go from soil to Coco? I've heard of people starting seedlings in Coco then transplant into soil, but not much the other way.