lol if the tips dry out its not from watering fool! its from over nuting, and that doesnt seem to be a problem, or it would stand out...

my best advice is to check the ph of your run-off, and keep an eye on the ph, also water it less, i havent watered my plant in a month, now its packin more resin than a rasta with a weed gun.. ive had edges curl exactly like that throughout the growth of a whole plant, and it was fine, i also had it do that on another plant which died fast, CHECK YOUR PH, FLUSH AND CHECK RUN-OFF and maybe use diferent water.. good luck