Leds vs MH ( for example) according to a published graph on zooxanthellae light absorption spectrums. There are AT LEAST 30 used by corals. Most or all ( even more, depending on the bulb) are present to one degree or another in MH. A LED unit usually has 6-10 color spectrums. So on paper, there is no comparison, no debate, no questioning on which light is more appropriate for coral health/growth. I rarely post in forums anymore but instead exchange with scientists, writers and experts. If any of you guys also do so, you would agree 5 pages on this topic is unnecessary. Can LED grow SPS= yes! Equally to MH or even T5= no, not yet. Keep in mind everyone's gorgeous frags under LED, see any 15" colony's grown from a 2" frag under LED alone?