scrog question

i thinking for my next grow to do a scrog.... i was told by someone not to use a 400 watt hps to scrog.... but i think i can... just wanted to see what everyones opinion was on it..... and if anyone has any advice feel free to post

I don't see any reason you can't just don't let it grow out on the screen too far.

what if i was to do a box of green? 400hps too much or not enough?