Yes, because the PAR (Photosyntetically Active Radiation) used for coral growth is higher in MOST 10k bulbs, and it declines as the color of the bulb shifts blue GENERALLY SPEAKING. Some 14k bulbs have really low PAR, some have high. There are a bunch of links in the SPS forum and Lighting, Filtration, Etc. forum about it. I promise that it'll be more worth your while to get a bulb that you like the look of, as they'll all probably grow your coral in your tank.