There are a ton of posts on this forum, many from me.
Short answer is that the proper types of LEDs grow corals splendidly.
Little heat, very long life with little PAR rolloff, much lower energy bills and safer than MH. They are also more environmentally friendly as they contain no toxic material. And now that the price is plummeting the LED is the light of choice. Add up the costs of the fixture, bulb replacement and electrical costs to get a full picture.