Metal Halide Bulbs

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mrpope

Aquarium Advice Activist
Joined
Nov 16, 2003
Messages
165
Location
San Francisco, Ca.
Is there a difference in quality between mogul based and HQI Metal Halide bulbs/fixtures? Is one better than the other?

B.
 
From what I have read, the major differences are that HQI bulbs are more intense for the same wattage, but do not have a UV shield. So that boils down to the light is stronger at the same wattage but you have to put a piece of glass between it and the tank or you will burn your fish. It can also be more dangerous to you if you are not careful.
 
My first thought was, I do not want to touch mine when it is one because it would burn to the bone, but then I got the meaning of the message. I may be slow, but I get there.
 
So that boils down to the light is stronger at the same wattage but you have to put a piece of glass between it and the tank or you will burn your fish.
Why dont they put a sheild with these? Should I get a cut piece of glass and try to fit it in there? I want an open top tank so I dont want to have a glass top.
It can also be more dangerous to you if you are not careful.
Is this because of burn risk?

Thanks everybody! :D
 
Is this because of burn risk?

This is true, but the other important risk is UV to your skin and eyes. You can easily get a pretty bad burn if you work under the HQI without a shield.

Why dont they put a sheild with these? Should I get a cut piece of glass and try to fit it in there? I want an open top tank so I dont want to have a glass top.

They do not put a shield on them because of the way they are built and basically cast in glass. The problem is that the glass is too thin to block the UV. The way you shield it depends on the way it is mounted. A small piece of cut glass a few inches off of the light will work, just make sure it protects out the sides as well.

These two reasons made me go with the mogul base bulbs instead of HQI.
 
i would have bought a reflector made for hqi which would have the uv sheild on it !! if not yea ya can add a piece of glass just make sure it will block uv light !! it basicly the same as a mogul bulb but the mogul bulb has glass around it keeping the uv it !! hqi's are larger guts of a mogul base bulb !!
no it dangerous due to the uv !! they say it could cause eye issues and skin cancer i'd guess !
 
i would have bought a reflector made for hqi which would have the uv sheild on it !!
The fixtuer I am looking at is a MH/PC combo hood, but I cant tel from the picture if it has the uv sheild, I am waiting for an email answer. This unit sparks my interest though because it comes with feet, so I wont have to hang it (I have vaulted ceilings). These feet look pretty sturdy (metal construction) and they suspent the unit 7 inches off the top of the tank. The price is also right so hopefully its got the uv sheild!

Thanks everybody, B.
 
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