What kind of deficiency or insect is this?

I’m in my 4th week of veg, and started noticing rust spots in Some of the lower leaves. Not sure what type of deficiency this could be. Or in what stage it’s at. Newer to growing so still learning about deficiencies and issues.
using
Coco choir Pearlite medium
Bio Bizz nutes
Roots organic Terp tea
And Cal/Mag
water ph’ed to 6.3 on every feeding