one of two things. its either nute burn, or that foil is frying the ends. take it down and put up white poster board. it reflects just as good without the burn. that is just my 2 cents. but then again i have a whole bag of pennies
Woody soil IS NOT good with pot plants. The roots can't move through it easily and your plants become stunted. Even when you transplant those leaves will never grow like the new leaves will. Learning experience man.
looks like some wisdom got thrown your way. in soil when you have nute problems flush with ph balanced water 3 times the pots capacity and readjust your nutes on the final pour so 3 gal. grow bag flush with 9 gallons of wata see ya good luck