Depending on the bulb/ballast combination, 20k's can be pretty weak, especially 250 watters. I think you could grow just about anything under this bulb and you 'may' be able to run it without actinics, I have a friend who does just that except with a Reeflux 12k. Heck, for 30 bucks its better than buying a new Reeflux for over twice the price then deciding you dont like it.