Can Cold Night Cause Some This?

[singlorigin]

Hy, so plants was super cool till this day, had a calcium problem , put thos to work . Plant was doing ok. Till i had my radiator switched of at the night and the temperature was a bout 17 C for 7 H , and in the morning when i came tu put new radiator, many leafs tips curled down and , got dry on the touch . Also with some many brown spots. I don't think its calcium again .
Also is it normal that new leafs are so green ?
Dont look at that por girl in the corner , don't think she will recover :( Taking her out .

36 day growing
PH - 5.7
Temperature water 20 Cjumbo
PPM - 800
Roots are looking nice and white
Humidity 47 %
Room temperature 21 C
Using GH nutrition's
Light on for 24 H and changed the water 2 days a go.

 

[Erick31876]

The crispy ones look cooked from the light. How far away is it.

 

[singlorigin]

The crispy ones look cooked from the light. How far away is it.

I did put it higher to 60 cm from the left side plant, but from the plant exactly at the top it is a round 40 cm . Using 2 LED creed 36 W lamos.

 

[London bud]

I don't think your problems are caused by cold air, 17° for 7hours ain't a problem. I think your problems are being caused by deficiency, no sign of nute burn or light burn imo. Try raising ph slightly for a week, different nutrients are absorbed at different ph's