I keep a small hobby garden, never growing more than 4 autos at a time (local laws). I used to use a 150w HPS, that won't cut the mustard for growing two autos to maximum yield. I'd suggest using a lot of CFL sides (1000bulbs.com has some great 105W compact CFLS that fit standard edison sockets), that or upgrading to a 400w hps. At one point I had 2 400w HPS and 4 105w CFLS running sides. Was pulling an avg of 2 oz per plant. Heat became a MAJOR issue, have since switched to approx 700w of LED. Bud quality improved, still pulling an avg about 2 zips per plant. Yes I spent close to $1,000 on lighting to upgrade to all LED, but the lights are under a 3 year warranty and are totally and completely bad ass. $1,000 is not a lot in retrospect when pulling a half pound out of my closet every 2 months or so.