MH Lighting height?

[clearerphish]

I have ordered a light fixture for my upcoming 55g reef project. Fixture has 2 175w MH, 2 54w T-5 Actinic, 6 lunar lights. I am building a canopy and stand myself, and need to know how high above the surface of the water would be the ideal hanging height to minimize heat transfer. Or even better, how close to the water's surface can I get these before it makes a significant difference? It's a standard 55 gal, 20 inches deep. Thanks in advance.

 

[Devilishturtles]

I would say atleast 12 inches with plenty of air flow (ie: fans attached to the canopy) to cool things off.

 

[clearerphish]

So 15" bottom of light to top of tank would be totally cool with a couple of fans on each side right at the bottom of the light?

 

[Devilishturtles]

Yes. You may also want a fan pointing at the water surface too, to help keep things cool.

 

[roka64]

I have mine about 6 or 7 inches from the surface of the water, it really heats the water and the room it is in.