yes dogfishfan i have cosidered hps, but getting one in my grow space & keeping temps at reasonable level would be difficult (i could make another fan useing lorry rad-fan@24" & 10"ductwork, but thats getting crazy big for 4 plants). if i go for led's i can put in a shelf at 65" and have a space ontop at 35" (top for veg under cfl and bottom for flower under led). but i still might make another fan anyway, the first one was so much fun to build that every time i come across scrap vehicles (for the fan), buliding sites (for duct/tubeing) my brain goes into overdrive.
Does anybody think its a good idea to squeeze another 4 plants into this space??