I have a 600 dimmed @ 75% due to temp and warm plug at 100%.. (10/2 waiting to go in to new 30a when friend has time.) It's only a 4x5 room, but whatever it can hold it will grow just fine. Like already said, it would depend on how big you need to get them. Wouldn't be able to veg 12 in 5-10gal, but if you just had up to 2 maybe 3gal you should still be able to veg long enough. I would guess 3-4 weeks and a couple transplants under it. I prefer 6-10 weeks of veg with lots of training. Have to fell the trees with a chainsaw. lol