ventilation

hey, ive decided im going to start growing. Im in the process of figuring out what i need. im wondering if a 250 ml exaust and a 150ml inlet will be enough ventilation for a 400w hps system in an area about 3' wide 1.5' deep and 6' tall. im not sure if im goin to have 1 or 2 bigger plants or do a SOG. Which one would anyone suggest to do with my set up.
also with the kit im getting you get some foil with it, its thicker than normal foil, should i use this in my grow box, will it cause any heat problems or do the advantages (saved light) outway any problems it could cause. thats all i can think of asking atm, but there will be more.
thanks for any help,
-matt

can someone please help me with this?????

you cant really do a SOG in that small of a space, unless you want a really small one. SCROG is much better for smaller spaces, it gets the maximum yield out of a plant. Get a 165cfm exhaust blower for your light, itll work perfect. IF you want good reflection matter, paint ur area with flat white paint, foil and mylar are not worth the time. Keep good ventilation with fans in the grow area, and try to get outside air to flow nicely in and out of the grow box. Good luck!

first of all i run a 400 w hps light in a box that 4ft wide 20 inches deep and 6ft tall. I used 2 265cfm blowers to keep the light cool and temps are still 85-89f so keep that in mind