I'm growing 4 plants in a large cardboard box that was originally for a disassembled costco desk chair. 25.5 Inches Long, 14 Inches Wide, 26 Inches High
I taped off all the edges and then wrapped the bottom of the box in a large black garbage bag to prevent moisture from the floor getting in. Another bag inside on the bottom to prevent any spills from getting to the cardboard from the inside.
I lined the inside with tinfoil (Glossy side out, dunno if it makes a difference, i just figured it diffuses the light better). I have 2 regular table lamps sitting in amongst my girls with 2 more hanging lights above them. A 12 inch fan taken from a computer case keeps circulation from above (i have it above the plants, blowing upwards into the 'attic' of my cardboard house)
The two long flaps on the top i left to make a 'house' type shape, and the smaller side flaps i taped up as well to close off the ends. In the morning i open the box and can feel a warmth, but its not by any means hot.
All the lights are regular household CFL's that i scavenged from around my house lol, i know at least one is 2400k which is better for flowering, but this is defiantly a ghetto grow! I originally had them on my bathroom counter growing beside 2 CFL's but they were really struggling, stretching, and their stems could barely hold the tiny plants up. After i put them in the box they've been doing MUCH MUCH better. My biggest one's stem is now as thick as my thumb.
I LST'd two of them onto their sides and they have many tops coming up from the main stem now. Some of the ones that barely grew in my bathroom are now doing amazing in the box. The nodes are much much tighter. The different heights in my lights i think is helping also, its penetrating between/under some of the tops and starting to cause them to branch out nicely.
I tried topping another one. I think i'll stick with LST and never top my plants again. It seems when you top your plant you aren't really 'making' new branches. You're just stopping the main stem from growing and forcing the top two side branches to become the new tops. Why not just bend it over and let all of the side branches becomes tops, and at the same time not damage/stress your plant? I think the only reason the side branches don't do so well is lack of light. Turning it on its side solves this. I've also been 'LST'ing' the fan leaves so they arnt blocking light to any of the branching 'tops'. I don't want to cut them.
The benefit of topping i guess is you don't end up with a really WIDE plant. LST'd plants are taking up a lot more floor space then my topped one.
Wow did i get off topic or what. But yeah, my cardboard box grow is going really great! I need more room though... I'm told they'll double or even triple in size after flowing, that might be a problem... I'm looking to upgrade to a broken deep freezer