With most fluorescent tubes, place the light as close to the seedlings as you can. For very intense fluorescent lights such as T5s, overdriven tubes, possibly some intense T8s, and compact fluorescents, place them a few inches from the top of the leaves. Use enough to provide coverage over all your planted trays or pots. Lights on for 14-16 hours per day works well, use a fan on the same timer or full time.

I suspect that I actually need more light than my GE plant and aquarium (fluorescent) bulbs are putting out, because the Dahlia seedlings are starting to really stretch. They look absolutely healthy other than that, though. Still, it's better than the almost nonexistent light at my windowsills, so I'll manage.

Lisa