I would love to find a 150w MH conversion bulb that would run in a 150w hps socket/ballast. I have one for my 400w but would be nice to have one for the 150. two 150w MH's sound like it would be plenty to veg anywhere from 18-24 plants to prob around 18-24" You'd light up an area about 3x3' or 3x4' very well. You could fit a ton of clones in there. I used to use two 150w HPS's and they would take 5-6 through flowering at about 3' tall. two 150's would be perfect for the average squarish closet (use lots of reflective materials on the walls) but MH for veg only, the spectrum is less than optimal for flowering (not impossible though). Keep em about 18-24" for seedlings and clones, then 12"-18" for more mature plants... JG106256 is right, feel the heat on the back of your hands at the canopy, if you're hot after a minute they'll cook spending alllll day long under them. blow fans UP and through the canopy toward the bulbs, blowing the heat away. You'll need decent ventilation for two 150's cuz Im assuming the ballast is attached and not separate. Otherwise you'll still need decent ventilation anyway if you're used to using CFL's. Search craigslist for some 150w Hps's to switch to for flowering, or a 400w. I found a 150w for $50 and a 400w for $100 there. I found two other 150w's a few years back for $30 each. They were used from a Budweiser brewery parking lot!
