Sick Girls.. Help! please

[Couchlockedchef]

50 days from seed
OF soil and nutes/CALIMAGIC
5 gal pots.
SF 4000 LEDs

The girls are showing these rust colored spots which have been getting progressively worse since week 2 of flower. Starting to see the yellowing of some leaves.Don't know where to start because I'm afraid I'll make the situation worse.

 

[MIAutomatic]

It’s hard to help much with so little info, but it looks like you are dealing with lockout from overfeeding.
Overfeeding is common with autos in soils, which if you are adding anything to before week 4-5 is almost definitely too hot for your plants.

If you put seeds in OF and then added more fertilizer before week 4-5 they are very likely over fed.

water source?
PH?
EC and or feeding amount and frequency, both is better.
temp?
Genetics?

that Is the bare minimum