MH height above water

[Solarreef]

What other reasons, if any, besides heat are the reason we should keep Metal Halides 8 inches or so above the water. I was just wondering that if heat were not a problem wouldn't it be better to get much more light in simply by putting it closer.
nils

 

[aquarist=broke]

water spashes on the MH and boom, catastrophe. I don't think my animals could handle hot pieces of glass falling from the skies....

 

[Bodine]

My halides(PFO pendants) are protected by glass cover.
I keep mine as close to the water as possible....about 5 inches...

 

[Anonymous]

none,and yes

 

[Bill2]

I've keep mine as close as 3". I've never heard anyone's bulb exploding. I've heard them cracking but not shattering. I'm not saying it hasn't happened just that i personally have not heard about it

 

[Kenny]

I plan on building a new hood for my 90 to house dual 400 watt halides. I plan on keeping them about 7" away from them surface. The main reason to keep them higher above the water is so that inadvertent splashes don't hit the hot bulb and cause them to break.
Kenny

 

[reefland]

I had 400w Ushio's explode running 6 inches from the water. Hard to say if a spalsh caused it as all the glass fell into the tank anyway. The glass cools almost instantly.

When I used to run single ended bulbs I always has to clean salt creep off the bulbs, a sign that they got splashed frequently. Now with a HQI setup the UV filters block any spashing.

Only draw back I see besides increased heat is less dispersion in the light field. Might not be an issue depending on how the bulb is mounted.

 

[Solarreef]

I recently bought two 150 watt HQI DE setups with a Sunlight Supply Reef III reflecter (with a glass shield maybe 3 inches from the bulb to the glass)...how high do you think I should have it over the water?

nils

 

[Anonymous]

My 175's are no more than 3" above the water. I put a sheet of acrylic below to prevent the splash/exposion problem. The acrylic is a PITA, it needs to be clean weekly. But it gets the job done and keeps me from worrying about the bulps getting splashed.

Since your light fixtures has a lens, put it a close as you like. It should be fine!

Louey

 

[Anonymous]

I had a tank accident, snail into overflow.

I used a clip on fan, the fan had no shroud, and was clipped onto the back of the tank, blowing towards the halides.

Picture a outboard motor

The water rose, until it hit the fan, the fan then turned into an outboard motor, and completely soaked the 250w iwasaki bulbs, when my kids dragged me into the room, the fan was still spraying large amounts of water onto the bulbs and out the back side of the tank. I hit the breaker, the bulbs were allready cool to the touch, and dripping wet

There was no cracking, or shattering or exploding, I think the iwasaki's are pretty tough bulbs compared to the others I've ran

 

[Anonymous]

I had a tank accident, snail into overflow.

I used a clip on fan, the fan had no shroud, and was clipped onto the back of the tank, blowing towards the halides.

Picture a outboard motor

The water rose, until it hit the fan, the fan then turned into an outboard motor, and completely soaked the 250w iwasaki bulbs, when my kids dragged me into the room, the fan was still spraying large amounts of water onto the bulbs and out the back side of the tank. I hit the breaker, the bulbs were allready cool to the touch, and dripping wet

There was no cracking, or shattering or exploding, I think the iwasaki's are pretty tough bulbs compared to the others I've ran

:arrow: 8O

wow!

 

[Nelliereefster]

It's rare to get a good blood-curdling scare like that, cherrish it, it's like blowing carbon out of your chevy!!!

 

[aquarist=broke]

I have occasionally splashed my MH bulb w/out consequences, but I figured I was an exception. Where I heard the "hot glass in tank thing", I think it was here. Today when I was moving rock around, I bumped my hand into it a few times. Burning pain, but no breakage. I really don't know now that i've read the above posts.... :roll: