Having issues with my first autos!

There girls are about 5-6 weeks old. My first time growing autos and i’m noticing some discoloration/yellowing leaves and rust spots. Anyone know if this is a deficiency or from over feeding?

You have bugs.

Thrips

^^^
this. Knockem down with some spinosad. You’re early enough in flower that it’ll be metabolized by harvest.

A bit of nutrient burn happening as well.

I had very similar issues with a very similar setup as yours.
My fan was even in the same spot
Came down to poor watering habits on my end. Bugs and all..
FFOF in which sat in the shed for a bit didn’t help.
Last time I buy dirt in bulk..
Also get that dead plant material outta your pots.