growbox

is a hps 400w good enough for 4-6 plants in a box 70x70x170 ??
should there be a bigger box or is everything ok to go ?

Are your measurements in inches?

nope cm metric units i am from europe

I'd say it's a go - provided you have adequate venting...

wat about a 250 better or worse ?

well technically a good rule of thumb is to go with 100W's per plant. id stick with the 400W. YOU MUST HAVE VENTILATION MUST MUST MUST. I cant stress it enough.