I've used a lava lamp fixture myself, 2 fixtures, i had it rigged so it was suspended above the plant and angled in towards the center with a height adjuster. i grew a single plant in the closet for a few weeks and it got about 4-6in. tall.. i used one of them new floro bulbs.. the ones that are bout as big as an incandescent, but made to save energy.... walmart has them.. i pick one that had a lumen rating of around 4,800 or somethin that was efficient enough to a certain point i don't remember.. however i got faster and better growth when i switched to 36" floro tubes