Nitrogen deficiency? What does everyone else think?

[Stretch1970]

Hello everyone, flipped 5 days ago to 12/12 and lower fan leaves turning yellow.

Here are a few images of the worst, I have looked on numerous posts and think it could be nitrogen deficiency, was just wondering if anyone else thinks the same.

I am growing in 100% coco professional

 

[NuttyProfessor]

you using led lights ?, hows the ph ?,

 

[Stretch1970]

Hi, 2 x 600w HPS and Ph is 5.8 to 6.0. I have read about fan leaves turning yellow but most say that is later on in flower it started after the second day.

I am using Dutch pro nutes. They recommend 25 to 35 ml per 10 litres I have slowly increased it to 25 ml during veg.

I have had a issue with high temps but sorted a couple if days ago.