how high off tank for mh

[newfish]

i have 2x175 14k on 38gl tank need to know how high off the water they should be

 

[meemoo]

Are you upgrading your lights to MH's or did you just change bulbs?

 

[steevareno]

6 - 12 inches but in a small tank your going to have a heat issue, so either put them high or add a fan blowing across the top of the water. This increases evaporation which keeps the water at a cooler temp but you have to add more topoff each week.

 

[newfish]

i had a canopy that keep them 2 to 3 in off water i just made a new canopy they will be 12 in off the water did not know if it was too high

 

[Ray]

well you shouldnt have a heat issue as much

 

[meemoo]

That will keep your heat down and if you find your corals are not growing try lowering them a bit. I have 2 250mh's 6" above water on my 56g. Does raise the heat a bit though

 

[newfish]

before pic

lights are mounted on the top of canopy

 

[newfish]

ill post after pic when i find my camara

 

[Scuba_Dave]

Mine are mounted about 9" off of the water

 

[this is me]

mine is about ten inches from the waterline.
It all depends on the dept of your tank too. The lowest I would do is 6"

 

[MarkO]

I've got mine 6" above the waterline. The closer, the more efficient, but you don't want them so close that a splash could crack them. Also, as mentioned, closer generally means more heat. If you don't have A/C in the summer, you're probably going to need to look into fans in your canopy.

 

[Scuba_Dave]

My sailfin loves to spit water when he feels neglected, so any lower is a problem for me

 

[cougaran]

I was kind of wondering the same thing as far as height.. Any recommendations for a 250 Watt MH over a 40 breeder-- strictly a frag tank?

 

[newfish]

new canopy

now the bulbs sit 13in off the water Iwant to make it 10in off the water.Ialso have to put door in front