3. It is 21x1.5x3=94.5

Not the other number.

So your fan is going to rock in there. If you haven't purchased the fan you you could easily step down to a smaller fan. Or get the larger fan if you think you may expand in the future. Either way you definitely want a fan controller. Just note, some fans are quite loud. Smaller fans make less noise. Do more research if this is going to be an issue for you. I can recommend some quiet fans if needed.

You can turn fans off with lights out so long as odor is not a major issue. They will start to stink up the place by the time lights come back on. You can experiment. Also, odor becomes an issue once you hit flower although some strains start to smell in veg.
bigsby Reviewed by bigsby on . Can I vent this? Hey so this is my first grow and i wanted to buy this Grow Tent and 400w HPS kit but i'm not quite sure how to set up the ventilation. is it ok if i just set up small cfm fans without ducting? i don't want heat to be an issue, but at the same time i want to keep it as cheap and simple as possible since the tent and light were pricey enough :) any help or tips appreciated! cheers Rating: 5