Grow boxes can be found on ebay, just got to hunt for a good deal. Most of the dealers offer them as private listings so you dont have to worry about looking at them and bidding on them. The pic below is one I picked up. It has a mother chamber on the right and a flower chamber on the left with a 400HPS in it. I run DWC in both chambers. The entire box is 23 inches deep, 42 inches tall, and 3 feet wide. I have a seperate box for clones. The HPS in the flower box has an inline fan attached to it that sucks the hot air out of the box, through the light, and through a carbon scrubber on the back of the box. The box also has a 4-inch inline airtake fan that I do not need to run, the air passively entering and the inline fan in the HPS is enough to keep the box cool since the HPS is sealed behind glass. Even with CO2, you will need to vent your growbox and this will require an exhaust fan. If you are growing a few seeds out of a bag for personal use then great. But if you live in a high traffic area, are growing something really funky, or are going to be flowering plants on a continual basis...sacrifice the money and get a carbon scrubber. It would be much more worth the peace of mind that the CO2.
