Purchase full-spectrum fluorescent bulbs. These are the best for seedlings as well as other plants.
Place seedlings about 12 inches (for flowering plants) to 36 inches (for non-flowering plants) from the lights.
Stick out your hand where the light hits the plant. If you feel warmth, the light is too close to the plant.
Rotate your plants each week. The light from the center of the fluorescent tube is always more intense, and less at the ends of the tube.
Provide the seedlings 14 to 18 hours of light each day. Day-neutral plants, however, only require 8-12 hours of light a day.