400hps IN 2x2 foot homebox xs? Bad idea?

400w in an homebox xs (2 x 2 ft) grow tent.

Heat is not an issue , homebox will be in a cold room , with a serious exhaust fan.

400w / 4 square ft ( 2x2 ) = 100w per sq-ft

250w would be 62.5w per sq-ft

I like the sound of 100w per sq foot but is 100w going to be a bad idea ( too much light for the plants to process??? ) remember temperature / ventillation is not a problem.
Ive read plants love lots of light, but there is a point where you are giving them more and more light, for less and less return ( and electricity consumption too )

250w Doesnt seem too bad @ 62.5w

I have my 1000 hps in a 1.5 x 2.5 x 5.5 =P ...waiting for a paycheck for a tent

I'd go with the 400... 250 isnt gonna give you much penetration (thats what I went from my 250 mh to the 1000) but I think if you went with the 250 you'd be kicking yourself in the butt..

..hell, if you wanted some taller plants and good nugs and you could raise the light a good amount even a 600 would be nice.

That's just my advice/what I'd go with from my experiment.

good luck man

Heat isn't an issue? Well, then go with the 400w for sure.