Top leaves are curling down

[Sampagani]

Hi everyone!
So it started yesterday with my Northen Light auto @ its 42th day : the top leaves are curling down! I checked here in the forum and it seems that it's a over-watering problem!
But the pot contains 12L of soil and to avoid the over watering situation I only water 1/6 (2L) only after checking the soil is dry about 3-5cm.
So guys, what do you think the problem is (if there is any, maybe I'm hallucinating).

 

[BigCube]

What are your temps like at their lowest? Looks like cold to me.

 

[Beachwalker]

"the pot contains 12L of soil and to avoid the over watering situation I only water 1/6 (2L) only after checking the soil is dry about 3-5cm"

It does look like over-watering and what you said above could be why?

you want that soil dry almost to the point where it starts to droop from drying out, not quite but almost, it's called a wet/dry watering cycle and it's a soil growers best friend.

Start picking it up and if it almost feels completely light & dried out that's when to water, hope this helps!

 

[growsince79]

Looks like you need to add perlite for drainage. Also you are watering to little to often.

 

[Sampagani]

What are your temps like at their lowest? Looks like cold to me.

yes it could be, I live in Tunisia and the weather in this period of the year is clod by night (14-16C°).
Yesterday I started lighting them with 250w HPS lamp and it warms the area! I think it'll be fix the cold porblem!

 

[Sampagani]

"the pot contains 12L of soil and to avoid the over watering situation I only water 1/6 (2L) only after checking the soil is dry about 3-5cm"

It does look like over-watering and what you said above could be why?

you want that soil dry almost to the point where it starts to droop from drying out, not quite but almost, it's called a wet/dry watering cycle and it's a soil growers best friend.

Start picking it up and if it almost feels completely light & dried out that's when to water, hope this helps!

Thanks!! I'll take in consideration your advice!!

 

[BigCube]

yes it could be, I live in Tunisia and the weather in this period of the year is clod by night (14-16C°).
Yesterday I started lighting them with 250w HPS lamp and it warms the area! I think it'll be fix the cold porblem!

Yeah that's a bit too cold .

 

[Sampagani]

Yeah that's a bit too cold .

Thanks again for your help! Leaves are recovering now : yesterday was a sunny day so I took them out under the sun and in the evening I returned them under HPS light and the heat to which they were exposed fixed the problem!

 

[BigCube]

Thanks again for your help! Leaves are recovering now : yesterday was a sunny day so I took them out under the sun and in the evening I returned them under HPS light and the heat to which they were exposed fixed the problem!

No problem, glad you figured it out
It's always an option to have the light on at night and off during the day to help keep your heat up.