Fixture question!

I just purchased a MH fixture-ballast, lamp, hood etc 1000w. Could I use a HPS bulb in this fixture instead--Im trying to cut down on the electric bill so for now I was going to use flouresent for vegging then use the 1000w for flower. Any help would be great! Thanks

hps is much better for flower but you must use a conversion bulb, like this one if you have a mh ballast. it is much better just to have an hps ballast for hps bulb though
http://www.plantlightinghydroponics....products_id=90

unless you have a switchable ballast of course

edit:
hps and mh won't make much of a difference on the power consumption. they are both hid lighting and use comparable power. cfl and flouros cost less to run.

Do NOT use a HPS bulb in MH ballast. This would cause a serious fire hazard.