easiest way to build either an 8' x 8' or a 4' x 16' sealed box ????

Yo!!! I just got 4x of the BML SPYDR 1200 and I want to build an airtight sealed box so I can use CO2.... I can't just build out the entire room because the area this is going into is about 200' x 400' (this is all for testing purposes) so... if I go to home depot, what do I need to buy to accomplish this? I was thinking a bunch of 4' x 8' and then some of the clear 6 mil plastic sheeting... I'd like to be able to easily access 2 sides of the box which are across from each other since I'll be hand watering... that is where I'm stuck at... thoughts??? ideas??? I think once I have a solid design I'll be able to build this shit easily.... thanks dudes!!!!

go 8 x 8

okay lets say I go 8 x 8... how do I put in like doors and shit that will be airtight? haha... I mean I dont wanna be ghetto and just use panda film as a door. I need to make it look kinda professional if that makes sense

Just seal the door with weather stripping. You will be fine.

And for watering u could always install a drip line

Go with a four foot flood and drain table. Line the interior with 4'x8'x1" corolite. Corolight looks a lot like styrofoam but is non-flamable. Corolite insulation sheets are mainly used in insulating concrete construction. In white it's great for light reflection and it's fireproof. Certain caulkings would be handy for sealing joints in the material. I prefer using a drill and deck, drywall screws etc for assembling. I would go 2"x4"'s every two feet on the framing to accomodate a door and just wrap it tightly in black/white plastic...white side out.

You could even finish the exterior with cheap colored tarp. A bag of 2' fiberglass inso's pretty cheap also.

Drywall for the interior is cheap and non-flamable but heavy and can get ruined if wet.

use cheap metal exterior door for entry. After installing door, seal with great stuff insulations spray foam. The door will be airtight.

6 pieces of wood.
Brackets,door hinge,screws,wood glue,paint ect pretty easy to make a "box', just use weather seal as people say for the door.
As far as c02 you can just slap a bottle and reg in there or just build an external cab that can push into the grow room.

I found a 5'x5'x7' mylar tent for 200 including shipping. Never used it but ive set up. Not bad. EBay is the way

I got this made up for me not cheap filling sealed door for co2. 3 point lock work great 8x9 grow room