I just wanted to add one thing :P The keep the
lights close to the seedlings part :P I learned that there is such thing as too close to the seedlings lol.. I have been keeping mine about 1 ft away from the plant though tomatoes can probably handle a little closer, i scalded a few of my other plants when I did try closer.
I am not sure just how close the plants can handle the lights, and the difference based on how your lights are set up. My lights are 128W in about 4sqft (4 32W 4 ft tubes all next to eachother) so it is a lot of light in a small area. That probably contributed to the scaled I recieved.