You just have to make sure you have dimmable T5 ballasts. All of the new controllers make it quite easy to dim with T5's as long as you have dimmable ballasts. Mine are incorporated into my Sfiligoi fixture (ballasts). I use my T5's for sunrise and sunset simulation and it's great. It's not necessary at all, but it's a cool feature if you enjoy the many bells and whistles this hobby offers : )