Originally Posted by acursedblade
Cheap version with small space, CFL's.
More expensive version with larger space, MH, HPS or HID.
I have seen large scale grows with CFL's *there were hella them*, and I've also seen small scale grows with MH, HPS, and HID's.
Only thing I personally stay away from are the LED's. Call it personal opinion but the quality of the bud that I've smoked that was grown under LED's was WAY below all the other types of lighting, but there could have been other factors too.
EDIT: If you grow hydro, someone I know set up a system that is 5 x 5ft and is made out of rain gutters. He grows between 30-45 plants per harvest and uses 1 1000w HPS per 5x5ft section