what kind of deficiency? Please help me

the seller said they didn't add any nitrogen fertilizer into the soil for seedling period. And I was wrong for using this soil so long, almost more than 20 days.

The symptom is like nitrogen deficiency, lower leaves turn yellow and new leaves seem all right but today! It's pale yellow the whole plant and even worse, I find some spots!

Yesterday and today I put them on the roof, is that spot light burns?

Please help.

Ya, nitrogen. Add some.

Are you adding nutes. Use vegging nutes , not bloom . Veg nutes are higher in nitrogen .

They look fine to me. That little spot on one of the leaves looks like sun burn so you might want to leave them off the roof.

Don't panic. Just buy some veg nutes. Add a very small amount to water. Like 1/10th of recommended dosage. Feed your plant that. Once it starts to perk up you can slowly start adding more nutes until you get to the full dosage.