Its all about how you use your nutrients! MG can grow plants just fine, you just have to read your plants and get to know them. Hey "66548" your plants definitely have a nutrient issue. If your problem was overwatering the leaves would be drooping overall... yours are clearly curling in on themselves which can be caused by a number of factors (heat and nuts namely). Though I am a newbie I would start looking at deficiency/overfertilizing pics.
I believe I caught my problem just in time. According to the back of the GH nutrient bottle, plants will not need as many nutrients if they are in a high lumen area. I definitely have a high lumen area!!! My ladies are always trying to get closer to the light.. I have lost a few little branches to heat, but the main kolas remain tied down and protected. My solution of course was to lower the nutrient concentration... My EC in is now 1.5 of a week 5 flowering mix. The result was immediate. They started filling in and getting dense the next day. Its only day 31 so I'm starting to get very anxious and excited!