The more light the better. Dejayou had a good point about tying down the plants a little. CFL's are only effective within a couple inches of the plant, so if you can use one light for more than one bud site, then you will get a better yield. Also, look at the Kelvin range on those. Flowering plants like lower K numbers, like 2700K (instead of 6500K, which is better for veg)