I posted a pic on my diy thread showing what uv does.UV helps to bring out that iridescent glow in sps. Also UV helps with coral coloration. The effect is not super noticable with the whites on. At night my RB TVs and UVs start off at 100% then slowly the RBs fade leaving the TVs and UVs sty at 100% the tank turns purple and the very subtle iridescent colors stand out. Its so cool to see.
