I've had really great success with led bulbs. I use fiet omni 13.5w led bulbs and have pulled a gram a watt with them. They are a bit more expensive but they are much higher quality(use to be found at lowe's). A good way to tell quality is by the weight of the heatsink...most of the cheepo bulbs at box stores are gonna have a plastic housing that will be really lightweight. I feel I get about 2x as much light, watt for watt. IMO paying a dollar a watt is still very cheep considering you should be able to grow 5x as much $ worth of weed the first harvest. I mean why nit-pick over a few dollars when your first harvest will be worth 100's of dollars.
still...even the cheap plastic led bulbs will out perform cfl bulbs watt for watt. I recommend removing the diffusers. A lot of the info and love for cfls is based on outdated info and threads. The tech on led bulbs has advanced so quick in just the past few years that it has made all the cfl grow threads outdated....which sucks because there was alot of work put into them and it can be misleading to new growers. Don't get me wrong I grew for about 3 years under flouro/cfls and had good results... but after switching to led bulbs I immediately had great results. There's no way I'd go back...I think I have a pile of 30+ cfls under my sink that will never get used.
Distances seem about the same..maybe an inch further from the led bulbs if the diffusers are removed. I can get about 2 inches from my led bulbs before I see bleaching/burns. With cfls I would run about 100-120 watts per square foot to see optimal bud growth. With led bulbs I can run about 60-70 watts per square foot to see the same results with slightly less heat. Also I used to change out my cfls every 2-3 flower cycles (4-6 months) .. I've had these led bulbs for about 2-3 years now and I've never needed to change one and I've never had a burnout. I had a few random burnouts with cfls within their 4-6 month period of use....just that fact right there covers the slightly higher cost of an led bulb.
