dude, you need to do yourself a favor and put a bigger light in there! i had a 400 in mine when i first got it and it was kinda dinky in there. luckily for me, the light died a week later after 3yrs of use, and i got a 1000w to put in there. the 3x3 hydrohut definitely needs more than just one 400 in there. another 400 would be good, a 600 would be better, and the 1000 is best! in such a large volume of space, the 1000 doesn't even heat it up much more than the 400. my hood isn't even air cooled right now and temps are around 75 at canopy level. also, you may need a larger charcoal filter to combat the stink from the number of buds you're gonna produce in that baby!
what's goin' on with all your duct work outside of the tent?
Thanks for the advice on the lights...after this grow I was maybe thinking of getting a 600 in there, but I wanted to see what I could do with a 400 first.
I wanted to make sure I had no worries about ventilation. My tent is in a walk-in closet that I keep shut and locked. I have a 170CFM inline fan in the room that draws fresh air in. The ducting runs through the door and then I split the ducting and added two 80cfm inline fans (one on each side of the tent) right before the ducting enters. I also have the exhaust ducting running down the right side straight into a custom vent I made in the closet. It allows me to drop the ambient temp in my tent in just a couple of minutes and seems to work pretty well and no smells!