height requirements for mh?

[saltyESQ]

I wanted to use a retrofit kit and place it in my canopy. There is pleanty of room under the canopy, but when I have seen fellow reefers tanks who had similar set ups, their canopys seemed extra tall. Is this extra height required?
are there any concerns by having the lights only 6 or so inches from the tank?

[GinaSofia]

dunno,but what happened with your Bar results?

[SirLight1337]

With metal halide over an Acrylic tank it is recommended to be atleast 12" off the surface of the tank. Hence why you see the extra tall canopy, also with more height you can avoid the heat transfer issue of a 300 degree metal halide bulb into the water. The extreme heat from the bulb/bulbs could cause the center brace to bow or become brittle which would result in eventual failure.

If you have a glass tank that isnt euro braced, then the standard canopy is fine.

[bugsy714]

water splashes can/will pop your bulbs along with serious heat tranfer issues. Be sure to get glass enclosed pendants, preferably with a built in fan to cool them

[glaudds]

Ditto on all the above... also the extra height makes it easier to work in the tank.

[saltyESQ]

hmmm, i am going to go back to the drawing board then....

:( i will be retaking the bar in Feb

[GinaSofia]

not to worry..you'll do fantastic in '06,we'll be crossing our fingers for you :) Perhaps you can teach a certain atty. some of the ethics you'll be re-studying ;)

[PsychoKnight]

You want a splash shield of some sort; glass will allow you to place it just an inch from the bulb, but acrylic is lighter and easier to work with. Then, a 4" computer fan is a must-have, possibly two, one in, one out. You can cut the holes on the far ends of the backside of the canopy so the light doesn't glare from the fan holes. Taller canopies make it easier to get your arm in the water, but others have placed shielded lights very low to the water by rigging a pulley system to lift it up, some even incorporate a hydraulic/gas assisted light stand to flip up the whole light assembly.

[jeffrey_ropp]

bergamer - Keep your chin up. You'll get there.

I'm also considering upgrading to MH. Got any pics of your current stand/tank/canopy?

Anyone have pics of a modified 6" canopy to allow for the extra space? Since my stand and canopy finish match, I'm reluctant to mess with it...

[jrcastro]

PsychoKnight
Will a 250Watt MH bulb be ok 2-3inches away from my 1/4" thick glass center brace? I would have 2 4" fans blowing air in/out.

[SirLight1337]

jrcastro

It sounds like that should be alright. As long as you keep a constant stream of air moving across the surface of the bulb everything should be hunky dorey. If the glass were to get heated to an extreme point and then colder water were splashed on it, you could have a big mess on your hands. If at all possible id try to position it away from the brace.

On my 40 i have a standard canopy, but no center brace.