Hello, I built a new seed starting system this year and so far it's working great. I've used a wood frame with a 4 foot shop light and sunny windows in the past, but I acquired an adjustable shelf and 5 more shop lights for free this winter. I bought adjustable light hangers for very cheap from amazon (lord forgive me, but they're so easy) and I've expanded my seedling capacity tenfold. For the shop lights, I use one "daylight" 6500K bulb and one regular bulb, these are T12 48inch. I read that it doesn't really matter, but using both a "red" and a "blue" bulb provides a wider spectrum of light. I purchased a heating pad this year, and I'm amazed how much faster my seeds are sprouting. I had broccoli sprouting within a day! I keep a light on this area with my wood frame light so my seedlings don't start stretching out to find the sun. Hopefully next year I can get turn the 60+ windows I've collected into a respectable greenhouse! Good luck!