Hey guys. Right now I'm planning a grow in a home built box. Its in a walk in closet that is about 10 feet deep and 52" Wide. I plan on sectioning off the back 38" where there is a shelf about 70" High. The box will end up being 65" High, 52" Wide and 38" Deep. All lined with mylar and most likely built out of drywall and plywood. I'm going to be vegging with a 400watt M/H light and then planning on flowing with 2 400watt HPS all with removable balasts (this is where that shelf really comes in handy). My questions are these. With 4 1/2 feet of height, factoring in the lights, how many plants. Will the 800 watts of HPS be sufficent to illuminate this space? Now is the hard part. There are no vents what so ever in the room so bringing in and removing the air is going to be the problem. How many CFM will I need to properly expell all the hot air off the top? I'll counter this with another blower pulling air in through the bottom and if need by I'll duct through the walls to the outside. I'll have small fans inside to circulate the air as well and keep my girlies strong. Smell is no problem(Live by myself) and all my friends smoke so they won't be questioning why it smells like weed in my place. So what I need to know is how to cool all these lights down. I will probabally end up getting some air cooled hoods for the HPS and don't think the MH will be that big of an issue. This is my 3rd grow had great success with my first two all bag seeds. Total of 15 plants and got 12 females over both grows. That problems that I was having in the past were all light related (not enough) So this time around I won't be having that problem hopefully. Any input you guys have let me know. I plan on building the box this weekend and the seeds should arrive next week sometime.