The 3000k and 2700k, I'd stay away from a 6400K they will slow flowering, found that out by experience.how long does the flowering period usually take yeah i also like smaller plants the lights are nice and tight with the plants they are short and thick was wondering if i should use both my 48w 3000k bulbs and the blue spectrum 200w 6400k? or just stick with 2700k x2 48w