need help with a grow box!

hello mate, dont take my word for the right thing to do, as I'm a newbie myself.
The way i see it is, You need at least 1.5 square foot per plant in width/depth, and with hight, as tall as you can.
Paint the inside of your box with flat/matt white paint, or mylar or similar.
A hole near the bottom of the box (light proof though, try a 90* bent pipe painted black inside, to prevent light getting in while flowering), A fan to blow accross the stems/leaves of the plant to keep it cool/provide fresh air (preferably one you can move as the plants grow), and a fan high up to suck the hot air out with another 90* bent pipe painted black inside for flowering. (computer fan will do).
Keep the lights (6400k) on either 24/7 or 18/6 till she's nice and tall (at least 1 foot), then switch the lights to (2700k) 12/12 for flowering, keeping the plants in ABSOLUTE darkness during the 12 hour night period.
As I said at the start, I am just a newbie, but I have watched a lot of DVD's and been reading here a while. I Hope this helps you on your way bud.

 

What i meant was a pipe (like the ones you get under your sink etc) to cover the whole you need for ventilation with a 90 degree bend in it. If you paint it black inside, the light wont reflect through it, thus preventing light getting in when you need total darkenss.
If you have a growbox 3ft tall, I'd say that you shouldn't veg it past 2foot, as I think the plant grows roughly 1/3rd of its hight in the flowering process.
Then again you could top the plant to make it bushier while keeping hight down, or LST it for the same effect, even try a 1plant SCROG, but we're getting in over our heads now that will involve a LOT of reading, so I wouldnt recomend that just yet if you are unsure about the process.
just keep it sipmle and pray you dont get a male.
peace

 

Not, the plant will double or triple in height during flowering. I wouldn't grow in less than 4ft height but that is me, I've seen some with less.