how high should i keep my metal halide bulbs from my tank?

[splnissan]

My tank is 21 high and my rock are stacked 12 to 14 high running metal halide 2 radium 400 lumenarc reflectors thanks ronnie it s a 125 g

 

[nyc reefer]

MH Height/Placement

Free Bump!!

I have the same question so I'll tag along. I have a 72ga Bow dimensions 48Lx18Wx22H and run (2)250w 20k/XM moguls they are aprox. 12" from the water surface.

 

[GurpM]

I have two 250 watt metal halides 12k that are 10 inches from the surface of a 75 gallon tank I don't see a temperature fluctuation at all partlybecause its the winter

 

[JARRETT SHARK]

i would go 10-12 with 400w

 

[GurpM]

Hopefully your talking about a single bulb cause I think that evan my dual 250 are to much sometimes

i would go 10-12 with 400w