400 watt grow light question

[420soul]

I'm starting my first grow soon. It dimensions will be:
30" wide x 4' long x 7' high. Was wondering; is a 400 watt
grow light too much in a small area like that?

 

[Propa Gator]

Nope. Rule of thumb; 50watts HID per sq ft. Two 250s would light more evenly.

 

[420soul]

Thanks for replying,Propa. I would like to add two 250s but I'm afraid that would almost double my cost. Do you think its necessary to buy a air cooled light?