Placement of new MHs?

[Ugla]

I have a pretty standard acrylic 100 gallon tank with a shout canopy for VHO lighting. I am going to rebuild it for 2 250 watt MH's. How far off the water should they be? and what about spacing from side to side? The inside of the canopy is about 16" x 55. Lights are mogul sockets with reflectors.

 

[bc_slc]

i assume you are saying 55L x 16W and you're asking how tall? MH are usually placed 8-12inches off the surface. Add to that whatever the reflectors take up and the sockets and you will be set. If you tank is 55" long, then 2 reflectors placed with dead center at about 18" in from each side should be good. That will give you:

18" from the edge -- Reflector -- 19" in the center -- Reflector -- 18" to the edge again.

Mat