theres many different K's of white light. 14000k to 20000k helps give the pop and growth. best of both worlds. also, it depends on the par reaching your corals. theres just has to be a good par reaching to them that they can utilize. since they are photosynthetic, im sure they have certain peaks of light they use to make energy, like plants. in the sea, i believe what divers see most of the time is probably close to 20k. last time i went snorkling in hawaii, it was more blue than white, but not an actinic blue.