the curling tips indicate this strain does not do well in the heat, also the burning tips are another indicator, if you had pure brown tips with no curling and slight striping on the leaves I would go with nutrient burn, but first just lower the strength of the light or raise the height so let them get some rest from the heat of the light, if that isn't working out after a couple days, look at your EC of the run off to make sure nothing is funky!