Stunted growth/twisted yellow leaves

[Sampagani]

Hi everyone!
So 24 days ago I started a new adventure (my first one) and I planted 3 Bruce Banner auto (from Monster genetics) in a universal substrate under sunlight the day and led light 135w 6500K by night.
15 days ago I lost one bruce banner due to overwatering (leaves turned yellow and the plant died).
For the remaining 2, everything was ok until 6 days ago when I noticed that the top is turning yellow (near the white).
I read that it's about iron deficiency, so I vaporized on the leaves nutrients with iron and the leaves turned green again but the problem is that the growth of my bruce banner auto n°2 has slowed (even if I noticed new leaves coming out in the 2nd floor).
Now watering is controlled and yesterday I watered it with 2L with nutrients (1/6 of the volume of the soil).
so I want your help to make the right diagnosis and of course give me a suitable solution with many thanks!

 

[OldManRiver]

That's light burn.

 

[Sampagani]

That's light burn.

And the solution?

 

[BurnzYzBudZz]

Scope for mites if it isn’t a pH issue.

 

[Sampagani]

Scope for mites if it isn’t a pH issue.

No, it's not a pH problem, my other babies are ok! (I have 2 northern lights auto and one Super sliver haze with the same soil and they are ok).

 

[OldManRiver]

And the solution?

Raise your lights. They will grow out of it.

 

[Sampagani]

Raise your lights. They will grow out of it.

Consider it down! What about sun light please? Is it better to leave it under led lights until full recovery and then expose it to the the sun light again? Or the sun light isn't harmful? (sorry if this question is stupid )
Thanks for your help!

 

[OldManRiver]

Consider it down! What about sun light please? Is it better to leave it under led lights until full recovery and then expose it to the the sun light again? Or the sun light isn't harmful? (sorry if this question is stupid )
Thanks for your help!

The sun light is what did it. They need to be gently exposed to full sun, 2 hours a day to start for 3 or four days, then 4 for a week, continue to increase.

 

[Sampagani]

The sun light is what did it. They need to be gently exposed to full sun, 2 hours a day to start for 3 or four days, then 4 for a week, continue to increase.

OK ! Thanks a lot.