What can i expect with a 400 watt HPS light

I just ordered a 400 watt HPS light, it should be arriving in a few days. I am also going to be using five 75 watt CFLs (and maybe more.) I have some seeds of skunk #1 and big bug x skunk #1 cross. I have a few questions, this is my first time growing with HPS lights.

I am growing in a 4 1/2 ft x 7 ft closet, it has a slanted ceiling (45 degrees) that starts 3 feet up from one of the long sides of the room. It also has no outside ventilation besides the room that its in. Will I be ok with a small fan for ventilation? My light does have a remote ballast. How many plants am i going to be able to cover with this light? If anyone has any sugestions i would apreciated it.

Thanks!

3'X3' square foot is the common size limit for a 400 HID light. In a space that size, I can fit four flowering female plants, in 10 inch pots comfortably. The more ceiling height you have, the easier it is to cool.

A small fan will probably work in the winter/spring time, not in the summer. You probably won't be able to close the closet door, the heat has to go somewhere...:rasta:...and you need a fresh air source.