I used 6500k and 3000k together and after a few months my plants started showing signs that they weren't getting sufficient light. So I switched out the 3000k for more 6500k and they started perking up. Not a scientific study, just my experience. This was for Phals, Oncidiums, and some other tropicsl plants, and I had them about 12 inches from the lights.
Last edited by Gage; 01-16-2012 at 09:37 PM..