I use a 540w combination of CFL bulbs in my seedling grow box, which is 65x65cm or 0.3 square meters. Now, for my flowering room, which I intend to build, I need to choose between a 400/600/1000 HPS bulb and some sort of LED bulb. I don't know how big the room will be, but since each plant will likely take 50cmx50cm at full growth, and I have 5 plants, I figured 1.5mx1.5m is adequate. The question is what matters more - the space itself (1.5mx1.5m) or the amount of plants in the room. For instance, if I'm not covering the entire room with plants (because I can fit up to 9 plants in a 1.5mx1.5m room), do I still need 1000w? Either way, how does this compare to an LED? I'm going to be spending something like 250-300$ for the entire HPS setup, so spending say 350$ for a 700w LED lamp seems like a decent idea. Like this - http://www.ebay.com/itm/5W-Chipset-Newest-Universal-Mars-700W-Led-Grow-Light-9Band-IR-hydroponic-Lamp-/380621785777?pt=US_Hydroponics&hash=item589ed38ab1 What do you guys say?