Should they be on when the lights are on, when temp is high or all the time for air circulation? Should they be on for seedlings that have just sprouted?
I'm running them 24/7 in my flower closet, temps have been between 76 and 84 and humidity 55-65, so I figure it can't hurt
[quote name='"Ch33sy"']Should they be on when the lights are on, when temp is high or all the time for air circulation? Should they be on for seedlings that have just sprouted?[/quote] Always. You should have an exhaust fan and an oscillating fan so you can strengthen your plants stem and branches, and cool your setup.
I'd agree on the oscillating fan, to strengthen stems and circulate co2 etc exhaust really doesn't need to run during dark unless you're having temp/humidity issues. if they aren't bad, you could set the fan on a seperate timer, and come on during light then once or twice during the dark or something