Halogen and Mercury Vapor reptile heat bulbs each have their own advantages and disadvantages.

Mercury vapor and halogen lamps are generally used as basking lights. For the most part, they direct heat into a small area. But they get hotter than incandescent basking bulbs.

Other than that, they’re not really the same. Halogens are only good for heat and visible light (although they do that really well.). This is similar to incandescents.

Unlike other heat bulbs, mercury vapor bulbs actually give off UVB rays, too. So depending on your habitat setup and your pets’ needs, you might just need the one bulb.

Halogen Reptile Lamps

Halogen bulbs are basically modified incandescent bulbs. They do give off more heat than standard incandescents. So you can get the same amount of heat with a lower wattage bulb.

To understand the difference, you need to understand a little (just a little, really!) about how incandescents work. These bulbs have a wire (called a filament) made of tungsten. When you turn it on, an electrical current passes through this wire. The wire gets hot and starts glowing, giving off light.

But the high heat causes atoms of tungsten to evaporate off the wire. This weakens the wire. Eventually enough tungsten has evaporated that the wire breaks. And the bulb has “burned out.”

Using certain inert gases inside the bulb helps slow down this evaporation. And that’s what a halogen bulb does; it contains halogen gas. The gas helps keep more tungsten in the wire longer. This increases the life expectancy of the bulb.

So in theory a halogen bulb will last longer than a regular incandescent. In real life, though, people find that these bulbs often have a much shorter life.

Why?

Because they’re ridiculously fragile. Little bumps and jostles can cause them to burn out. This is especially true when they’re hot.

But if they’re treated carefully, they really do last longer.

Halogen bulbs also give off a brighter, whiter light than regular incandescents.

Zoo Med and Exo Terra both make halogen bulbs for reptiles:

• Zoo Med ReptiHalogen (read our ReptiHalogen review here)
• Exo Terra Halogen Basking Spot

Mercury Vapor Bulbs

Mercury vapor lamps are all-purpose bulbs. They give off heat, visible light and UVB rays.

That said, they’re best used as basking bulbs, because the heat and UV rays are highest right under them. There’s not much away from them.

If your pet doesn’t really bask, he may not actually get enough UVB from one of these. A tube UV lamp plus a different heat bulb may be a better choice for you.

On the other hand, the UV put out by these usually penetrates farther than many other UV bulbs. So if you have a tall habitat and have to hang it well above your pet, he can still get the UV he needs.

These bulbs do get very hot and can overheat a small enclosure. You can’t use a rheostat or lamp dimmer with these bulbs. So if you can’t find a wattage that doesn’t overheat your pet’s home, you won’t be able to use them.

Also, the high heat makes it very important you only use them in a lamp fixture with a ceramic socket. Anything else can be a fire hazard.

In theory, these bulbs can last a full year before needing replacement. But you probably shouldn’t go longer than a year, because even if it’s still giving off light, there may not be enough UVB coming out to do your pet much if any good.

See if any of these mercury vapor bulbs fit your needs:

• Zoo Med PowerSun UV (See our PowerSun UV review here)
• Exo Terra Solar Glo Mercury Vapor Lamp
• Fluker Sun Spot Bulb

Tips to Maximize the Life of Your Halogen or Mercury Vapor Bulbs

Both halogen and mercury vapor lamps can be a little delicate. Since they’re rather expensive, you want to make them last as long as possible.

Try these tips to help maximize their lifespans:

• Use only in a ceramic socket. This is also a safety tip to prevent fires.
• Try not to move them around too much (and never when hot).
• Put them in a spot where you, other family members, or pets won’t bump into them.
• Never touch the bulb with bare hands. Oils on your fingers can create hot spots, so either use a cloth or wear gloves when installing.
• Keep it dry. So if you’re misting your boxie’s habitat while the bulb is on, make sure you don’t accidentally hit it with the spray.
• The bulb should make solid contact with the metal tab in the middle of the light socket. If you’re not sure it does, pull the tab up a little to give better contact.

Hopefully you now have a better idea of whether or not you want to try a mercury vapor or halogen lamp for your boxie’s habitat.

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