Hello, what's problem on this?

Now I'm growing nirvana K2 with AG,
from some days ago (now is about 14 days)
I could see weirds on a leaf like this.

Could somebody tell what this problem is?

Lightless? Bacterias? Nutrition?

Plz help me.

are you giving them nutes?
maybe an MG deficiency. look in the growfaqs.

pH is probably a lil off