Help leaf browning

Been reading a bit on here to help with my first grow. Any advice would be appreciated. Told this isnt a big issue but thought i would ask more to be certain. Growing a sour diesel with rock products. In week 9 of flower, starting to notice a brown color with the leafs twisting on two plants. Got 24 plants under 4- 1000 watt HID air cooled hoods. Two carbon filters with inline fans, inline intake as well with 4 oscillating fans. Hydro deep water culture bucket setup. MM grow. Just started 30 more on another 4- 1000 watt hood system. No problems with any other plant, just two in the corner of a 24x30x8 space. Heat has increased with the added lights to 85, humidity 55%. Nutes are at 2.2 EC right now, about to do a water change. Not sure if this is a heat issue and need to exhaust at a faster rate to keep temp lower or if nutes need to be changed out/adjusted. Room is sealed with insulation and covered in plastic to protect environment from outside issues. See pics.

First your light screws up the pics so be prepared for that. 2.2 EC is unreal crazy high. I think you identified your problem. Leaf tips are blanched/brown/burnt from nutrient burn but unsure at what growth stage.

Thanks, and I will be sure to turn the lights off next time.