Hey blades, Starting up my grow room which i have been contemplating for a while now. The space i have is very awkward and im going to try to explain it to you as i have no pictures presently. The 'closet' im using opens into my room and dimensions are 3x3x7, All walls are already painted white and there's a drop ceiling which i plan to vapour barrier off. Now blades heres where it gets interesting, when i open the 3x3 closet on the left hand side theres a small doorframe that opens into a tiny 'walkway' that then leads under a set of stairs (stairs into the basement). Picture a set of stairs in a basement and your standing 3 feet back and one foot to the right of being under the topmost step and that would give you the placement of my closet in relation to the stairs. The little walkway that connects them is quiet small and even harder to explain so ill get a picture tonight. I have plenty of power brought into this space as well as a dryer vent that leads outside (flex hosing). I looks like the 3x3 closet used to house a washer and dryer before i moved in - awesome. Now my issue here is deciding which part/s of this space to utilize. The 3x3x7 closet can be easily vapour barried off from under the stairs and the walkway but i fear 3x3 isnt enough room for a 400hps setup. But the reason im hesitant of using under the stairs and the walkway is because the routing of flex ducting to under the stairs is going to suck and i only have 1 100cfm bathroom fan at the moment. It would also be hard to seal it off air tight and would require a full vapour barrier being put up. Now I can easily add another bathroom fan but im still stuck to the 4 inch flex ducting. Will adding one more 100 cfm fan to 4inch flex tubing be a bad idea? If i was to cut off the 3x3 room from the rest of the space that would leave me with about 63 cubic feet of space and only one 90 degree bend in the flex tubing. I would only run 1 100 cfm bathroom fan if i was to do this as i think it will suffice. So i guess my question is can i grow a 400w hps setup in a 3x3 space? looking to do 2 plants lst hopefully. Or should i just use the whole space but bump up my ventilation somehow (ideas appreciated, hopefully ideas that only involve a hardware store visit). I understand if i get no responses until i get some pictures up.