I grew a few full harvests with a 200w full spectrum. They work jsut as wellas anything else if close enough.mushka got it right 6500veg and 3500bud.+rep mushka
but with cfls get the biggest one you can get and you will be fine,me i got a 125w 6500k 12000lumen mogul base bulb and it works just fine and dandy. with spectacular results