I was looking at Champion Lighting's web site and notice that they have an awesome looking 180 reef tank that packed full of xenia and SPS corals. To my suprise, it is lit with only with four 72" VHO lamps. I was expecting to see halides and the whole ball of wax! Is this typical performance of VHO? If so, why the demand for metal halide lighting if VHO is sufficient? What am I missing here?