I been running mine at 70%+ all the way through veg and the preflower stretch but I haven't got the nerves to run it that high during the mid to late flowering stages. I am too afraid of bud rot and Powdery mildew problems! Although, with all the airflow I have I don't think I would have a problem. I am just not willing to take that chance after a long veg time and buds starting to show. According to the VDP chart the higher the temps the higher the humidity should be to a certain extent. Of course, I lower the temps in flower also. I have been getting exceptional growth with the LEDs. I was seeing faster vegetative growth while running higher humidity with the HID lighting as well before switching to LEDs. Good luck and happy growing my friend!!