Im about fo grow with 6500 &4100k in tandem because if you use weins law and divide the max absorbtion of nnm in chlorophyll A&B of 660&440 u get cor temps that correlate.....
3,000,000/660nnm=4545K
&
3,000,000/440nnm=6818k
Making the bulbs of choice 6500k and 4100k as opposed...