MH height above tank?

[j_treat911]

I've read that you should keep your MH six inches or higher above the tank. I have a 40 gallon acrylic with a small black hood that fits just over the opening of the tank rather then a large wooden hood that goes over the entire tank. I wanted to get a retrofit kit to put in this hood but that means the MH are going to be only a few inches off the water. Is there something I can do about the heat that is going to be transferred to the tank? What other problems might this cause? If this doesn't work then I'll just try to build myself a taller hood but I would rather use the existing one if possible. I wanted to get your inputs first. Thanks.

 

[tizzo]

You have, what's been referred to as, a freshwater hood. MH's should be 8-10 inches from the waters surface. Looks like you might hafta build another hood. IMO

 

[wwfstyle]

on my 75 I have my 2 250 MH about 12" above the tank. If you have them closer you will run into heat problems
. So I would say at least 12".