By the looks of it there is some nute burn, hence the little brown tips on your leaves. Although your plants look really good, except of the couple of leaves turning brown. From what I can I see I suspect some ph issues within the growing medium. To adress the nute burn, think about less is more. Give about 1/2 strength of the adviced dosage on your nute-bottles, only up the dose when you see her starving. Make sure the ph is right every single time, you've probably read it a thousand times but that's the basics of growing her dankness.