Over time the question will not be answered by what is best for the coral but what is best for the planet. LED's will continue to improve in their ability to match the Halides and T5's performance at a much lower energy foot print. So the coral will be fine and being living creatures will adapt. The original light bulb, incandescent, is now, or will be shortly, a thing of the past and no longer available. Likewise, as LEDs improve they will take over because of controllability and lower power consumption. No matter what your experience or opinion is, all technologies will eventually get replaced by newer technologies. We no longer ride horses to work, run trains with steam and, in the near future, we will not be powering cars and trucks with internal combustion engines. Take a look at the Tesla Roadster or the Amazon fleet of electric trucks and you can see the future direction we will be going in. So for now, Halides and T5's have their place. If they are working for you, fine, but accept the fact that they will probably not be available 20 years from now. I'm a photographer that started with film in the 60's and I haven't shot on film since 2000 when I replaced my Nikon F4 with a DSLR. Do I miss film? Maybe a little but I can do so much more with digital. Give the LED technology a chance to develop and, like DLSR cameras, it will far exceed the abilities of the older lighting systems.