Light Suspension Height

[Delphinus]

Originally Posted by outtafocus

Why do so many people run their MH so far off of the waters surface.
I have my 150w about 2" above the tank and I do not experience any heat issues.

My corals never seem to take off like others I have seen, is it possible that I am too close to the water?

I find if my light is much higher I get a lot of shadowing in the tank.

Remember though, 150W lamps put out only a fraction of the heat that larger wattages will. Plus, I'm assuming you're running DE, which means your fixture will have a cover glass. Most assuredly any unsheilded lamp at 2" above the surface will eventually crack due to splash.

Anyhow in answer to the original question, I run my halides about 6" off the surface too.