Plant : CFL Ratio.

[Roughrider]

Work is out by lumens per square foot and you'll get a better idea. 2,000 to 2,400 lumens per sq. ft. is adequate; over 4,000 puts you into solid grow area. Over 5,000 is great.

Most 23w CFLs put out around 1650 lumens. For one square foot, that's three bulbs. You can get away with less when vegging because the plants take up less space. If you keep your plants in 6" (around 1 gallon) pots for a while, you can veg 4 plants with only 3 of the 23w bulbs. But once the plants start to really grow, you're going to need more light. That why veg cabinets can get away with fewer cfls and lumens; they have smaller plants, at least for a while.

Flowering is when all the growth really takes place; you'll need more light then. So the big question is how big do you want or expect your plants to get? In my experience, one decent size closet grow plant takes up around 1.5-1.75 sq. ft. That's 6 to 7,000 lumens to do well...85 to 100 actual watts of CFL per plant. If you keep your plants small, you might be able to get away with a little less.

[klondike_bar]

so its agreed that 3-4 bulbs per plant for best results?

guess ill add another cuple for my nest gro

[eggrole1]

I have 6x26w CFLs on 2 plants that are 4' each. Don't let yours get that tall as the lower branches of mine were not getting enough light, so I trimmed them quite a bit. You would get the same yield with shorter plants with the light reaching all of the plant.

I started with 2x13w CFLs and upgraded as they grew. I would not recommend anything less than 3x26w CFLs per plant, and if possible arrange them in a triangle around the plant so that all of the plant gets even light. Don't forget to have some kind of reflectors if you can get them to help from losing any of the light.

As was said before, keep the lights as close to the plants as you can w/o burning them. (usually about 6")

[klondike_bar]

with a cfl id suggest that its safe going as close as 3" due to the incredibly limited heat they make