Finally starting my own room

Hi Guys,
So finally I decided that I wasn't able to afford spending so much money on buying, so I thought it was time to grow. And here I am. Yesterday I got myself a 400w MH and I am now itching to start.
I have a room which I thought would be perfect, it is about 2x3m big, but now I read that for a room that size I will need more lights, is this true? If so, could someone explain to me how I figure out the optimum size for a grow cupboard that I could make in that room? Also, what would be the best thing to do to make the room smaller? Would I have to build a box, or is there a way I can do it with plastics ext? Also, my light did not come with a reflector, I have looked up a bunch of DIY reflectors, but I was hoping someone could point me towards the best one someone can do on a low budget?

I am starting in soil, because I would love to just get the feel of it to start off with, and then I am hoping to implement bubblers for a hydro system a little bit further down the line.

Thanks for your help guys
Irie

proud to here that i believe someday we can all out grow babylon! haha
HAPPY GROWIN ND MUCH LOVE

yeah man u can basicly build ur own frame out of plastic piping using t joints and 90% bends, some one on here yesterday pointed his out to me,, u can build them for very little, in ur case 400 watt mh u would want a space coverage of no more than 5ft x 5ft section such n area off using the plastic pipes that u would then line with white plastic sheeting or mylar etc, or u could hang up ya light in a good spot in ya room then form a partition around this 5ftx5ft area no need for a cieling on it, just like a wind breaker at the beach except in ur case it will be lined with white plastic sheeting as to reflect as much light back onto ya girls ! but when u they start to flower there probly gonna stink so u will av that problem to deal with also u want good fresh air intake ( if poss ) ducted from a window or somethink, stealthy of course ! and as re ur reflector mine was £12 that come with the wiring n plug etc just screw in ya bulb n ur good to go, i seen some guys setup he just used coke cans opened up flattened out and then used these as reflectors as the inside of bud cans and some fizzy drinks r just shinny inside and is looked gr8, but if not u will av to pay around £ 12 for one,, good look on ur adventure hope it goes well, feel free to ask away as u go man ! peace out !

OK that sounds perfect f1 bud, question is how high should it be and also surely if there is no roof then a lot of light will escape?

http://www.ebay.com/itm/COMPLETE-400-watt-ORGANIC-GROW-TENT-w-LIGHT-KIT-SYSTEM-/400220157054?pt=LH_DefaultDomain_0&hash=item5d2efaf47e
have a look at that and try to build somthing of a similar size. remember not to use up every inch of your room as youll have cables and ducting to come out. its also handy not to push it right up against the wall of your room due to condensation forming on the walls.