I have been wondering whats the big advantage of running MH instead of t5 lighting if there is one. Considering t5 uses about 40% less energy to reach the the same light output as MH and the light fixtures cost about half what MH do. Plus MH puts of UV rays which i have learned will bleach the coral near the top of the tank after long periods of use. This makes me wonder if i am using the right light, i am running 500 watts of MH right now. There is also led lighting which the fixture is very costly. But the benifits are nice they are very energy efficient, there dimmable, and the bulbs have a life of 11 years, they also have very minimal heat output. I hope to be running a second tank in the next couple months and i dont want to be running 1000 watts or more of just lighting power if its not needed i guess is my point, if you can get the same results for alot less power why not . Any advice would help.