Need some input.

I know baugherb used a 150w MH on his 5.5 gallon. lol that is ALOT of wattage for that small of a tank. I think you would be okay. Lower wattage would be better, but mounted higher up, or hung from the ceiling could probably work? Not an expert on MHs but just throwing in my two cents. Good luck! keep us posted on the decision you make.

 

it would be a funny looking canopy it would have to be tall :400w is for 24" or deeper and i would hang it at least 18" above that for heat issues so what 3ft

 

Yea it would be lol. I ended up hanging it from the ceiling and the light it 19 inches from the waters surface. It looks a little weird i guess but not suppose to be looking at the light right?? I will up date in a few weeks or so to let everyone know if things are bleaching. Only thing im worried about really is algae.

 

well how deep is your tank... if its say 18 inches i think a mount with a good flashing around all sides about 2 inches above water would do good along with a glass top

 

if the light is se single end mougle base than it is already shielded

 

I have a 250w over my 20g. It sits on legs probably 6"-8" over the water surface. It has a built in cooling fan, I've never had a heat problem.

 

Light hitting the water's surface decreases by the square of the distance above the water. Double the distance, decrease the light by a factor of 4. If you hang it high you'll be fine (if the aesthetics are ok!). - Paul