HPS distance?

[madfreek]

Hi if i was to use 250w hps lighting, how far should the bulb be from the top of the plant? Also how far would a 150w lamp have to be? Any help would be great a limited grow space.

Thanks

[shaddr3]

6-8 inch minimum.

[Sensi Super Skunk]

http://greenmanspage.com/guides/lightguide.html