Your humidity is too high at 70%.
Those low leaves going spotty may be nothing to worry about, since it's only a couple leaves, and low leaves get ugly over time- it's normal.
I can't see thrips or their damage in those pics but look closely for silvery trails where they chewed the leaves, and poops, and little larvae about 1-2mm long and tan colored.
The pale plant in one of those pics needs a pH runoff test done on it pronto. You may also be over watering.

Edit: Zooming in, I see potassium deficiency or lockout in the pic where you are holding the leaf. Test your runoff pH of all plants showing rust colored spots. Usually that is associated with wet, acid soil.
stinkyattic Reviewed by stinkyattic on . PLease help gurus... spider mites? pics incl. here are a few pics of my babies. they are all clones, 1 skunk, the rest AK . They are about 1 month into vegging. 24hrs a day. they looked real healthy until yesterday when i noticed these spots on a few of the leaves. also i noticed some leaves with small holes in them. leading me to believe that i have some spider mites. i am using soil(promix) , the nutes i am using are liquid karma and sensi grow. temps sit in between 70-80 and humidity in between 50% to 70%. i have good exhaust with a 4" Rating: 5