CFLs are fine from start to finish. What you have to keep is mind is two things. The type of light used in vegging and the type(s) used in flowering. Veg plants nead light ranging anywhere from like 5,000 - 6,500 Kelvin. Also known as "cool" light. Flowering needs lower Kelvin temps, like 2,000-3,500, this is reffered to "warm" light. Also how many lights as apposed to how many plants. When you shop for light check for the amount of "lumens" your getting. I like to through anywhere from 1500-1800 Lumens for each plant while they veg.