lower leaves dying

Hey guys, I’m brand new to growing, I was spending waaaay too much money on smoke, so I figured I’d try to grow my own. This is my first grow and everything was running smoothly but now that I am noticing the little hairs where the buds will be, I’ve also noticed some lower fan leaves with rust...

Pants are in 65 gallon smart pots outdoor in "super soil" mix. I water them every 2 or 3 days as needed. All plants have the exact same growing conditions and are exhibiting the exact same issues. Its a little hard to tell from the photos of the inside of the plants because I've been picking off...

(sorry for my shitty english) My oldest plants have been presenting these dark spots in the lower leaves, always start in the second set of leaves and move upwards, slowly drying and killing the leaves. I'm watering with tap water, ph between 6-7 (I'm measuring with some shitty ph strips), I...