Thanks very much, Deb. I would rather be more certain of my info before calling it an "Idea". I saw too many divergent opinions about what tubes you "can" use with what ballasts, or "should" use.
I think that T5 tubes are evolving so fast that, by the time that technology stabilizes, LEDs may have come down enough in price to replace even T5s!
P.S.
I stopped buying more humidity domes when I realized that Saran Wrap did as good a job. I happen to have an 18" wide roll. This way, if half of a tray emerges before the other half, I can cover or expose whatever I want to. (You could use a dry-cleaning-bag the same way, or two strips of 12" Saran Wrap.)
I cut mini-blind slats in half or thirds, and use them like tent-poles to hold the plastic film up off the soil, especially when I have tiny seeds sown on the surface.
