dude im in my fifth week of flower and my top three sets of fan leaves on the main stem have canoed, and my problems were thrice bro. I had a heat problem in the top of my grow space, so i had to add another exhaust fan and build a carbon scrubber for the excess smell, im doin hydro and my ph level never holds for longer than a day so i got some real ph down not the fish tank shit i been using and that holds it cool for like three days at a time so far.