Metal Halide Question

[gon4x4n]

Good Morning, well over the weekend I found a guy that had 2 175watt Metal Halide Pendant lights and ballasts for a great deal, so I will be using these rather than buying a Power Compact fixture or replacing my florescent bulbs.

I do have a few new questions however, I was reading in a book that I have about the one drawback to Metal Halide is the UV, and that you shouldn’t look at the lights. I am really concerned about this because I have a 9 month old that parks his walker in front of the tank and I don’t want to worry about anything the UV affecting his eyes or anything like that.

Are there shields or something that can go on the lights to protect against this UV? Or am I just paranoid by what this book is saying.

Also I only want to run these 2 lights so would 14,000K bulbs give me a good balance to have vibrant fish colors but also enough blue color?

Thanks A Lot

Brent

 

[shr00m]

well actually theres no point of putting shields on the light, your gonna block them from your corals.... this is one main reason why its beter to put your lights in a hood or something similar so the light isnt blairing off the side of the tank when you look at it... not only does it not look good, but it isnt good for your eyes.

 

[shr00m]

another option is to make some type of wood shield that just goes up onthe front of the aquarium, like that just goes up enough to cover the bottom of the ights, then the lights wont shine out , just down...

 

[gon4x4n]

Thanks for your input, maybe I'd be better of to pull the sockets out of the pendants and buy a reflector and put them in a hood.

Thanks again!

 

[gon4x4n]

TTT

 

[Modo]

You could build a "psuedo" hood. Like someone mentioned above, build a hood without the top. I personally would build it too about a 1/2" higher than the lower lip of the pendant.

You can trim it out with molding or whatever you like. But, still allowing for lots of air exchange while keeping the light in. I've seen these set ups before and they look just as nice as full on hoods.

Taking them apart wouldn't be too hard either. Just purchase some reflectors and wire it to the existing hood. Hellolights.com actually have some on sale for $29 a pop that include the base. I just purchased some myself yesterday.

Good luck, but I wouldn't sweat the UV too much. Just block anyway you can stare into them directly. The water and glass will do the filtering through the sides of the tank.

Here is a link to the ones I purchased. You might shop around, but I chose these based on cost.
http://www.hellolights.com/methalparref.html

 

[MattM]

Are these single-ended (screw-in) bulbs or double-ended (HQI) bulbs?

If they are single ended, then UV is a non-issue. The glass of the lamp itself is a UV shield. If they are double-ended bulbs then you absolutely must have a glass shield in place. Looking at the unshielded bulbs for just a few minutes will give you a nasty case of flash-blindness -- basically a sunburn on your corneas. Not permanent, but your eyes itch, ache, and water for 3-4 days.

I speak from experience.

 

[gon4x4n]

They are single ended bulbs, I think I will be building a false/open canopy before turning on the lights for the first time, until then I'll keep running the old flourecents.

thanks

Brent