What can or will happen if i...

Plants are 3 weeks into flower and i need to stop running heater...$$$...will it hurt them more to turn off the heat or should i turn off the fresh air fan off more, im scared to turn off the incoming fan and mildew spike?? Any help is great ...have to make a call asap... Thanks

What are the temp's you are dealing with?

temps now i try staying from 70 lowlights out, highest 80 lights on outside temps tonight low of 50 tomarrow low of 42

i've yet to see plants dead, or even harmed, from low ventilation
maybe it's been done, but you don't need all the much of an air flow to keep a plant happy
provided the temps don't get too high, so you use the bulb(s) as your heat source, and save some $