i have heard that 6500k(daylight) spectrum help to promote females if used alone(no other spectrum) but not sure of the results. But a mixed spectrum is also healthy for the plant. Get at least 2 to 3 cfls per plant for now... and add more lower around the plant as it gets bigger. if you train the plant in a circle like i do you can actually pack a fairly powerful cfl in the middle of the plant.