Ok lets simplify it as babygro obviously either works for the cfl makers or is blowing 1.When I say use hps light as cfl sucks I am saying,...now follow me.per square foot your yield will be greater if you use 1 400 watt hps hid light then 6 smaller cfl light bulbs.I also imply this to my comment of cfls suck to the fact that with an hps light the difference in the bud density and mass will by far out do a smaller cfl grow.I also have stated in my other posts that you can grow nice plants with cfls if you buy the correct bulbs which are the larger 150-250 actual wattage cfls.These bulbs are large 18 inches in length and cost about $85 each without reflector so you would need a couple to equal the area coverage of a single 400 watt hps light so that comes to my point of hps setup actually being cheaper as a new 400 watt digtal switchable ballast is only $99 and then $29.99 for a lightwave reflector.Now that being said.As far as heat Myself an others who have played with cfls all seem to independently find that multiple cfls in a small are will raise temps just as much if not more then a single 400 watt light.The cost to run a single digital ballast for 24 hours a day all month adds about $20 to your electric bill yes more then running 6 smaller cfls but without fail you will yield more.Now as far as variables if you dont know how to fertilize or feed a plant either way cfl of hps you have that same issue.Lighting is 1 factor but indeed is a large factor in plant development.Color, lumnes output, and area coverage are all gonna be affected by that single choice.I make my comments based on the 100s of comments of new growers who dont even know about cfl color differences or lumne output.Its just easier and simpler to use a single 400 watt light setup and is actually cheaper to buy but you do have a slight increase in our electric but I also explain if you use the cfls to replace your home light bulbs the money saved there will offset the $25-30 electric increase from a single hps setup.Now Im game to take a challenge from anyone who wants to grow cfl setups of 4 plants against me growing 4 plants in soil non the less under my 1 400 watt hps light.Rules would be you can use 8 cfl 42 watt bulbs and Ill use 1 400 watt bulb.Winner is based on dry harvest weight, bud density, and finish time.You can choose any strain youd like and Ill use 1 I have.Im willing to bet $100 or 1 brand new 400 watt digital ballast.Pictures must be updated every 3 days a sign with FF in the picture and dated and I will do the same with challenegers Screen name.We start 2 threads as journels.Weights must be shown on digital scales clearly showing no tampering.Im confident so like I said make your cfl point and take the bet if anyone can honestly prove thier point cfls are not inferior to a hps setup.