Metal halide distance from water

I am building my canopy - just wondering what the ideal distance to the water is for MH. I am putting two 150w HQI bulbs in the canopy. My tank depth is 20".

Thanks-

Shane

my MH hood has an acrylic shield ... what would you say the distance would be in that case?

To quote our lighting expert "the ideal height for your lights is slightly submerged".  So if you can, put them just under the water surface.  Otherwise I guess above will work.

Adam

I would love to see someone's tank with submerged lighting. I guess you wouldnt need any supplemental heating

ssilcox,

There are actually a few of us who have had submerged lighting.  Almost always this is due to the clips breaking off the VHO or compacts.  I remember coming home one day and saying "wow my tank is bright today".  Then I realized my bulbs were sticking down at about a 45 degree angle down into the tank sitting on the rock and corals. 

Some others have had this happen, they just may not come out and admit it here.  But I'll tell you who there are later

Adam

I also came home one time to find my tank brighter then usually.  2-55 watt white bulbs were submerged in my tank still shining bright.