That’s a very hard question to answer. The obvious wavelength, is defiantly different but even when you compare different manufactures 10K and 14K bulbs the color and par are different. The closer to 6500K you get the more growth the corals have. The closer to 20K you get the better illumination of the coral’s zooxanthellae which will provide the neon look. The best I can say is to visit tanks that have different bulbs and see the color difference and see what you prefer. I preferred 14k bulbs by Iwaski
For growth go with the 10K and supplement with actinic
Hey Greg - I apologize I had originally typed up a reply when you first asked me this but my Ipod crapped out and I lost it and didn’t have time to resend - and subsequently forgot about it.
Al hit the nail on the head above. Since you are already running actinic supplements, you would ptobably want to go with 10Ks, 12K at most or you may end up running too blue.