Quote Originally Posted by harris7
the only benefit to CFL's is that they give off little heat.

...you would need to buy 4 200W clf's... So 800Watts of power....

hmm. They seem like a great idea for really small grows.
hehehe... Exactly. I grow in an enclosed closet 18" x 36" x however high I need to. Currently I'm running 5 plants, but usual is 4. (they're small)

CFTs are available in a varity of spectra. My favorites are daylight (6500K) & warm white (2700K). Stark white (5500K) is also good. Cool white (4200K) is so-so.

I'm using 189W of CFT (7 x 27W CFT) which gives me 11620L for 4.5 ft².

At bud time, there are 126W more going in (3 x 42W CFT 2700K/2600L) bringing the total to 315W / ~ 19000L.

The L figures are deceptive: the plant tops are much closer to the bulb than the spec measurement distance, the bases of the plants are about 10" below the bulbs.

I could not run a 400W HPS in that closet without major ventilation modifications which would defeat the purpose of doing it in the closet. Nor could I place a running 400W HPS bulb 1" away from the plant.

If I was running an actual grow ROOM, I'd go w/400W HPS. But for small, enclosed grows, CFTS rule!