I've been using them, from seed, to now bud. Grew great plants in short time, been a week into budding, and they are looking beautiful, I have (1) 4ft, (2) 3ft, (1) 2ft. (of course I have (2) 25watt cfls and (2) 42watt cfls, don't forget the 3ft all purpose grow light) -Will be replacing lights with a 400watt hps soon fo 100dalla. (includes ballast, ect)