Hi and welcome to GardenWeb! Because fluorescent lights are only able to provide enough beneficial light to the top several inches of the plants, they need to be as close as possible without burning the plants (normally just an inch or two). However, your T5 bulbs are going to get quite a bit hotter than T8 or T12 bulbs would, so you may have to keep them a little higher than that. I don't use T5 bulbs, so hopefully someone who does will provide more information for you.

Art

Hi âÂÂart33âÂÂ, you're right. Fluorescent lights are beneficial for some plants.