Sealed growing chamber

[Fuzzydevil]

If I wanted to use a sealed growing chamber... Besides a fan, and artifical source of CO2 (yeast) is there anything else thats required beyond normal. I have spent the past week reading all the guides to growing so think this should work but is there any other MUST haves you can forsee in a sealed growing chamber ?

Ill spell out what its probably gonna look like...

Using 3 2 foot flourescents. 2 softwhite, and 1 flowering specific light. (think thats right)

Box is 3w x 4l x 3h. Sowing about 8 seeds and weed out the males forcing each plant to flower on one branch at about 2 months or about 8" whichever comes first. And weed all but 1 male. Using about 8 inches of soil should give me about 20 gallons of soil or so. Continually clip back the male so it does not grow to large and take up any space and allow the females to grow vertically up to when each hits a wooden bar set in the box. Then using twist ties have the weed grow along the stick. This will increase the plant lengths about 2 feet with most of the plants finishing the vege stage at 4-6 feet. During the vege stage the plants will be in 24/0 and will slowly decrease over a week to 13/11 give it another 2 weeks decrease it to 12/12 and leave it that way pulling the male plant and using it to polinate only 1 or 2 female flowering branches for seeds couple weeks before harvest keeping it frozen until then in a ziplock baggy. The CO2 will be maintained using a gallon milk container with yeast/sugar/water mix. Its proven and it works well and its cheap. All light will be sealed in, planning to use sticky velcro along the box and the back of the lights so ya can adjust the lighting along the side of the box as needed since all of the light will be sealed in the box should be WELL enough for 4 or so 5 foot plants, even though it doesnt seem like it. Combined with the white siding of the box should work out well... Think that about covers it.