Yellow/brown marks

Hey there.. Tried looking thru your diary at the specific soil used but this kinda looks like some over feeding.. autos don’t need too much nutrients If you’re feeding extra nutrients I’d stop.. the cal mag may have left a few little spots but it’s nothing to worry about you can apply cal mag like that anyhow. Read some on your plants and I have to say doing mainlining on an auto with little experience is quite risky. If you’re doing it just to experiment and don’t care the results that’s awesome and I say go for it.. but if you want decent yields and whatnot I’d recommend just topping and LST or maybe just LST on its own.. mainlining/manifolding is better saved for photoperiods in my opinion. Good luck man!