Quote Originally Posted by Dizzy1
If your only going to be using CFLs you'll want at least 6-8 (more is you can) 40 watters. Those put out about 2600-2800 lumens.

You'll use the "cool" to veg and then have to switch the bulbs to a "warm" to flower.

So you're looking at 6-8 of the cool and 6-8 of the warm.

And I wouldn't let them grow straight up, the CFL's won't penetrate the foliage down low and your yield will suffer. Read about LST-ing to keep the plants lower and increase your buddage.
Exactly right. Except I'd use daylight bulbs all the way through for maximum lumens. With so little light to work with, if you switch to warm white for flower, you should also add more bulbs.