Light Suspension Height

[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.

[christyf5]

I have mine about 6" off the waters surface, mostly I was more worried about splashing the bulbs, plus the tank stand is pretty high and by the time I got the hood on there was only a few inches before it hit the ceiling (low ceilings in the basement) so mounting them higher wasn't an option for me (not that I would have done it anyway )

[mr_alberta]

You will get more spread with your light the higher you mount them, but you reduce the intensity of the light the higher up you mount them. Mine are about 6-8" away but my lumenarc reflectors still put a tonne of heat back into the tank.

[christyf5]

Originally Posted by mr_alberta

but my lumenarc reflectors still put a tonne of heat back into the tank.

Crud, I was hoping you wouldn't say that Good thing I have my chiller.

[TheReefGeek]

I have mine that high up so that I can work on my tank. My light is suspended, but stupidly I didn't put it on a pully system, so height adjustment is not easy.

If it was 6" above the water, I would have to move the lighting every time I wanted to put a frag in, or target feed, etc. And hoisting a 6 foot long lighting hood is anything but fun.

Once I get my pully system running, then I will run the bulbs 6-8 inches to get more intensity, but avoid some splashing that might burst a bulb.

[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.

[demon666]

i have mine about 10" above the water maybe too high

[Aquatic-Obsession]

sweet thx for all the great replies everyone.... what is the common way most of you suspend or have the light over the tank? I like the idea of a pulley system however this will be going in the living room so I need something that is asethetically pleasing to the eyes as well....

[Skimmerking]

Well that is why I went with the 400's mine are about 12" give or take a inch. My tank is 24 deep and I have Bare bottom. and my squamosa love it so i guess I enough light.


mike