how high above the water line should metal halides and PC be?

[seattle989]

Im building a canopy as we type and am wondering how high above the water line should i place my 250watt metal halide and 5 power compacts bulbs over my aquarium.


THANKS

 

[seattle989]

6-10?'' above the water line?

 

[fishoutofwater]

thats about right.

 

[mfinn]

I have mine at 9" above the water.

 

[Herefishyfishy]

I have mine about 5" but only 175 watt bulbs

 

[mfinn]

I asked the same question several years ago and it seemed the average was about 9" for 250 watt mh.
Some go higher, some go lower.
One thing, I did notice a trend with the lower heights.
Many of those that responded to my question that said they placed their mh bulbs closer to the water, many said, " be careful of the hot bulb, it leaves a nasty scar."

 

[seattle989]

thanks everyone i love this site soo fast. I think im getting fatigued Ive stubbed my hand 7 times already with a hammer but im done haha building woot

 

[roscoe]

I have my 250 9'' above the water line.

 

[windwaterwaves]

The closer to the water the less ventilation space to remove heat.. The light isn't going to be affected by air.... But the reflector focus may be. My guess is if the focus is right you could put the bulbs up 100'+ with no effect.. So inches are about the angles of the reflectors and trapping air space....