CFL Grow; Perfect For PC Grow Boxes-

How well do CFL bulbs Grow Plants and Why Do People Use Them?

Not everyone has a big space to grow in. When space and heat are an issue such as in a pc grow box, HID's become less practical as you are faced with either rigging a cooling system which could involve cutting holes in walls, ducting, and more power usage, and of course more $$$. Or what if you're just growing a couple plants at a time to keep your own fruit bowl full, and don't want to go through the trouble of HID lights? CFL's are everywhere, in all shapes and sizes, and are CHEAP. Most need no special fixture, and can be placed much closer. They are a great way to start out growing, keep a small crop going, or use with HID lights. With practice, your CFL grows can rival your neighbor's HID grows, even inside of a pc grow box.

Types: CFL's come in mainly two flavors, Soft White (color temperature 2700k) and Daylight (color temperature 6500k). For a complete CFL grow, you should use both. Soft white mimics the spectrum of a HPS light, and is best suited for flowering. Daylight's color spectrum is like that of metal halide lights, and is excellent for the vegetative stage. (This applies to tubes too. Around 6500k for veg, around 2700k for flower.)

CFL Grow for Vegetative Stage

-There is a large difference in vegetative growth when going from soft white to daylight. Therefore I recommend you use daylight CFL's for vegging, because they do not stretch the plants. You don't need much light for good veg growth in a pc grow box, especially when using 6500k CFL's.  26w per plant can suffice to a decent size, but more is always better.

CFL Grows for Flowering Stage

-Of course, use 2700k soft white for flowering. I have no results to back it up, but I like to use a single daylight bulb while flowering too, just to balance the spectrum. Whether it helps or not, it's more light nonetheless.
-I wouldn't recommend using any CFL under 20w, because it's just too damn small. (Remember, when talking CFL wattage, refer to the actual watts used, not the incandescent equivalent, i.e. 26w CFL = 100w Incan.) Lights of America is a cheap brand, and while they work, they don't last as long and fail prematurely more than other brands. GE and Phillips are big names, and make a more reliable and slightly more powerful product since they have a name to uphold. Monster CFL's 65w and up work great too, either a self-ballasted screw-in type, or the type that needs a special fixture with the ballast built into it. They can pump out lumens like a HID. Again, my Lights of America 65w Daylight burnt out in a week, but it was 11 bucks and easily replaced.

Using CFL to Grow: One of the advantages of CFL's is that they screw into any normal light socket. Therefore, mounting options are endless. Take into account the size, shape, and heat given off by CFL's when deciding how to place them.
CFL's are not as intense as HID lights, so distance is critical. You don't want your lights more than 4 inches away from your plants.

-Reflecting light is important with CFL's to use every bit of light they give off. Use good reflectors, paint your walls flat bright white, or get mylar.
-However, if your CFL grow is too close it may burn the leaves, so trimming or a fan may be needed (recommended anyway for stronger stems). Bigger bulbs obviously are hotter than smaller bulbs. Fluorescent tubes can touch the plant without burning it, but an average CFL will roast anything it comes in contact with. Even 26w CFL's burn. You want to get close, but not too close. Try to stay about 1 inch away. Having a fan blow right through the plant over all the lights helps get them closer. And monitor your plants so they don't grow into the lights. If you're going away for a week, move the plants down in anticipation of your plants' vertical growth.