How High off the water???

[Kyleighsdaddy]

I am building a canopy to house my lighting and fans. How high off the water should the lights be mounted in the canopy? The light setup is a 440w 48" VHO with 2 actinic, and 2 whites?

 

[redmonkey0019]

I had basically the same lights over a 55g aquarium, I had the bottom of the bulbs 6" from the waters surface with no heating issues.

 

[areze]

I had mine 6", raised it as high as I could now, 9"

mine are MH, raised them because I was getting salt spray on the glass.

 

[benjavan]

Light that reaches the surface of the water at greater than a 30 degree bounces off and is wasted. Figure out what height puts the edge of your tank at a 30 degree angle from the bulb and that will determine what your optimum height is. If you have any questions, I know I saw a link to a site that illustrated this well. I will try to find it for you.