I think the brown spots are from to much H-2-O, not enough O-2. I never let my plants completely dry out though. These autoflower plants grow to fast to recover from stress, so if u let them dry out to much, it will stress them out; and the outcome will decrease your yield by at least 10% maybe even 20%. Also to much water can bring on Fungus Knats, these little fuckers will break you off something nasty!!! They eat the fungus in your medium around your roots and even eat your roots (which scars the roots), and when they are done eating that they will go and eat your foliage, in which can cause those brown spots.... By the time you start seeing spots on your green, the bugs that could have caused these spots are long gone dead and reproduced more offspring; so-on and so forth... your MJ does look pretty nice though.
Good Luck and Happy Growing :thumbs:
Good Luck and Happy Growing :thumbs: