HQI bulbs (no Glass Shield) for Reptile Care...

[asnatlas]

I know that if an HQI bulb is used without a glass shield it will put out UV... I am just wondering how much and if it would be able to be used in place of a MVB (Mercury Vapor Bulb) like the ones listed below...

ReptileUV (http://reptileuv.com/)

T-Rex & ZooMed (http://www.reptilesupply.com/index.php?cPath=26_33)

I planned on picking up a UVB Meter, I was just wondering if anyone had any input on this before I looked into it further...

[PaulErik]

The UV output from a mercury vapor lamp is different from a HQI metal halide lamp. An unshielded HQI lamp will cause eye damage and skin damage from short wave ultraviolet rays. A mercury vapor lamp does not allow short wave ultraviolet rays through the outer bulb. Some mercury vapor lamps emit long wave and little medium wave UV.

[RichConley]

HQI bulbs with glass shields still put out a lot of UV.


HQI bulbs without shields will pretty much melt you skin theres so much UV.

[asnatlas]

<a href=showthread.php?s=&postid=10210373#post10210373 target=_blank>Originally posted</a> by PaulErik
The UV output from a mercury vapor lamp is different from a HQI metal halide lamp. An unshielded HQI lamp will cause eye damage and skin damage from short wave ultraviolet rays. A mercury vapor lamp does not allow short wave ultraviolet rays through the outer bulb. Some mercury vapor lamps emit long wave and little medium wave UV.

So an HQI bulb would not work for reptiles since it does not put off the same UV rays...

If you don't mind me asking how do you know what you have stated above ??

[asnatlas]

<a href=showthread.php?s=&postid=10210378#post10210378 target=_blank>Originally posted</a> by RichConley
HQI bulbs with glass shields still put out a lot of UV.

HQI bulbs without shields will pretty much melt you skin theres so much UV.

Do SE'd bulbs also put out UV ?? I am taking it that if they do, then its prob diff UV rays then reptiles need ??

[PaulErik]

Any high pressure mercury discharge (mercury vapor/metal halide quartz arc tubes) emit dangerous UV levels (UVA, UVB and UVC) and requires some type of shielding for safe exposure to people and animals. An unshielded lamp like a HQI double-ended MH lamp is totally made out of quartz glass which passes through all types of UV.

You can find many warnings and other information about unshielded Mercury and Metal Halide lamps all over the internet or documents from lamp manufacturers.

The mercury vapor lamps used for reptiles is equipped with an outer bulb that shields some UV and all UVC from the arc tube. These are safe and while an unshielded HQI lamp is not.

Some large reptile holding places like at some zoos they use regular metal halide lamps such as commercial MH400/U and MH1000/U lamps. These lamps can be operated in an open light fixture (without a glass shield) if operated vertically (base up) and have a good amount of UVA and UVB. The other bulb shields some of the UV but all of the UVC is completely shielded.

Lower wattage MH lamps are not recommended due to the increased risk of the arc tube rupturing and should only be used in enclosed fixtures equipped with a glass lens. If the arc tube ruptures the outer bulb could shatter and expel extremely hot glass into the environment. The added lens will block even more and some times all of the UV. For lower wattage setups it’s recommended to use Mercury Vapor and Fluorescent lamps which can be operated in open fixtures safely.

Manufacturers do make lower wattage single ended commercial MH lamps that are open fixture rated but these lamps have an additional glass shroud around the arc tube but these usually cut 40-90% of the UV making them unusable for UV lamps for reptiles.

I can tell you from first hand experience exposure to an unshielded MH lamp is painful and well cause cell damage in a very short amount of time.

[asnatlas]

PaulErik, thank you very much for your posts... I am always looking for new and different things because so many items can be used with different applacations but when you buy something for a specific "hobby" it can tend to be more exp just because of marketing... I guess in this situtation it will not work as planned...

[therman]

Actually I have tested an unsheilded HQI (250W Ushio 10,000K) and many other bulbs using a decent quality radiometer with a detector measuring from 280-310nm. There is very little to no UVB in this bandwidth (the response curve of provitamin D3) emitted by the unsheilded HQI I tested. All the "harmful" UV emitted must be of different wavelengths, so they are of little use for herp husbandry.

There is a cheap alternative out there however, certain halogen bulbs produce the proper wavelengths. Hopefully it will be published in the next year or so.

-Tim