How high should I hang my light?

[RyanP]

I have a 2 x 150w mh fixture over a 48 x 24 x 12 shallow tank. I currently have it 10 in from the water surface. Too high? Too low?

 

[RyanP]

Bump

 

[Mock]

I would put it down as far as it will go and then step back and look at it.. If it looks like you are shining a Q beam into the tank then they are too low... Raise it up until you reach the threshold of having it look like its lit from above but not have it look like there are lights shining strait into the tank.