oh, and one more tip (you probably know this, but just in case...)

To keep the plant as short as possible, keep your light as CLOSE as possible. Just dont burn your plants. With CFLs, you can get very close (around an inch...) without harming the plant. This will require raising the light about every day.

Use your hand to test how close you can get. If your hand doesn't burn, your plants wont either.