is it possible to veg with hps?

I wouldn't use an HPS just yet. For the first week or two, I would use some cool white 40watt CFLs. 400 watts on all day for 2 weeks is a lot of money to start off seedlings

 

yes it is very possible but i agree with firstgrow, CFLs would be a more efficient solution for a couple of weeks.

 

$5 worth of electricity is nothing compared to plants that

1) take less time to mature
2) yield more
3) have a higher success rate

If you use the CFLs, put them right up close to your plants. The 400 can be a longer way away.

Your goal should be to wean your seedlings onto the bigger light as soon as possible.

Try turning the light on for an hour a day and see how they do. If you think they can handle it, switch to the 400 and they will get big, fast! Be sure they don't get too hot, other than that, remember the golden rule:

Light = growth!

-zb -->