This is how they look an hour after lights coming back on.
Still a little droopy looking
If they still look droopy tomorrow after the light go off then come back on, what should I do?
Your choices...
1. figure a way to let that hot air out of your tent since you're running 62watts per sq ft or
2. don't turn on your de-humidifier, let the humidity rise at lights off or
3. leave your tent open with humidifier on during lights on
IMO, your air exchange is not fast enough to compensate the heat produced by your HID lighting
This is the reason why I asked where's your tent at, because of the huge fluctuation of your temperature. You're lucky that we're coming to Winter and you don't have to deal with extreme high temperature inside your tent. Something you might have to plan for Summer, maybe switch your HID to 800 watts or switch to LED, anything to reduce heat inside your tent.
With my set-up (LED), I still have a temperature difference within 7F between inside and outside of my grow area. From time to time, I just leave my grow area open during lights on.
As to humidity, temperature effect your humidity, so if you have a wide fluctuation of temperature so does your humidity. I too deal with low humidity (low 30's to low 40's), my plants struggle during the vegetative phase but I'm 6 weeks in of flowering and I'm good with the 30's and 40's humidity.
Hang on there, do what you can do to manage the heat and get through the vegetative phase. If you can pass that, you'll be happy with your flowering phase.
