Quote Originally Posted by Zandor
You can if you have an enhanced bulb like the Hortilux bulbs
That's right. If you get one of those bulbs, you can use it throughout its whole life.

If you just use a standard Hps bulb for vegging, it doesn't produce enough UV rays that the plant needs during that time. The result will be stretched out budsites, that in the end will be light and wispy.

I find all these different bulbs confusing as well. So I use CFL's for vegging, and a standard Hps I bought from the Co-op Garden Center for flowering. I'm happy so far with this setup, as I am still learning the ropes and I don't want to spend a wad of cash till I'm ready