Hi, my name is Colin. I work in the sales department here at Tye-Dyed Iguana, and today we're going to be
talking about mercury vapor bulbs and their use with your reptiles. So there's a couple different
brands of mercury vapor bulb on the market, and the main thing that's going to set your
mercury vapor apart from your other UVB products, like your compact and your linear tube UVB bulbs,
there's a couple different areas. So firstly, when we talk about UVB we often talk about
penetration, and penetration being the distance that is sufficiently going to provide
UVB with your reptile. So with your mercury vapor bulbs, in comparison to some of your other
bulbs, like your linears and your compacts, the penetration on a mercury vapor bulb is going to be
3 feet or about 36 inches regardless of your wattage. With some of your linear tubes and some of
your compact bulbs, that range is going to go from anywhere from about 2 inches with your daytime,
just tropical light, all the way down to your intense UVB, which is probably going to top out
about that 22 inches, but with the mercury vapor you're going to have 36 inches of penetration.
The main difference on the wattage between the bulbs, is going to be the heat output. So the
great thing about a mercury vapor bulb, is going to be your all-in-one bulb. A lot of the bulbs on
the market, they're either going to be UVA or UVB. So when we talk about UVA it's typically
your infrareds, your nighttime infrareds, your daytime incandescent basking bulbs,
but the mercury vapor is going to have both the UVA, which is that beneficial light, and the UVB,
which is that basically radiation that's needed for your animals to produce vitamin D3, to
synthesize calcium in their diet and to basically prevent things like metabolic bone disease,
which can be common in captive reptiles that are kept without UVB.
So, mercury vapor bulbs, how do they work? It's going to be a little bit different than some of your
fluorescent tubes or your linear tubes. So, in a mercury vapor bulb it's a little bit different
of a concept than in your standard incandescent basking bulb. In the mercury vapor bulb there's no
filament what actually happens is here there's a gas, there's an inert gas, just like in your
other bulbs. It's hard to see because a lot of these designs are frosted in the front now, to
maximize the spread of light. But basically, there's an arc tube inside here and it's filled with that
mercury vapor gas, and how it works is basically when an electrical charge is sent through that
arc tube, it starts to cause the gas to heat up and eventually that's what's going to create your light.
When you turn on your mercury vapor bulb at home, you may notice for the first
a couple minutes there's a very soft faint blue glow, what that is is your arc tube is
just starting and essentially starting to warm up that gas. The other thing about mercury vapor bulbs
that's going to be a little bit different than some of your other types of lighting,
there are several different varieties of mercury vapor bulb but all the ones we carry in our store
are called self-ballasted. Basically a ballast is a device that regulates the electrical supply, uh,
to a bulb, and in these bulbs here they regulate their own electrical supply. So we oftentimes
receive a lot of calls from folks, they just got their mercury vapor home, they're putting it in
the cage for the first time, and it's running for a couple of months, and all of a sudden they say, well,
my bulb was on and then it just turned off, it won't turn back on. Um, in most cases what this is going
to be is generally the result of an overheating, and this is a built-in safety feature that's
included in the mercury vapor bulbs. So basically there is a high pressure gas that's in the bulb,
that's your mercury vapor gas, that's basically ignited by that little arc tube inside there.
Whenever the ambient temperature inside the bulb becomes too hot, essentially we know as gas expands
the pressure increases. Whenever the pressure is too high, that arc can't occur between the
components inside the bulb and so that is why your bulb is going to automatically shut off when you
overreach a certain temperature. Some common causes for this as well, are going to be a power surge.
So anytime there's an interruption in the electrical supply to your bulb, because that
bulb is what we call a self-ballasted lamp, it regulates its own electrical supply, whenever it
detects a fluctuation or a change in the amount of electricity it's receiving, it's automatically
going to cut off that arc, as a safety feature to prevent shorts, to prevent the bulb exploding,
different things like that. So if you've had a power outage, if there's been a surge
of any kind in your home, or if you just simply unplug the lamp and plug it back in
quickly, that bulb is may not immediately turn right back on, and that's going to be one of
those safety issues. So what I usually recommend is let the bulb sit for 10 or 15 minutes, uh, see what
it does, and then most of the time that bulb's gonna turn right back on, just because of that
safety feature within the ballast. So now we're going to talk about basically what I like to call
longevity of your UVB bulb, and we all know that UVB bulbs, eventually that output over time will
decline, and then eventually just disintegrate. With your mercury vapor bulbs, it's going to be
the second longest output of UVB in terms of reptile lighting. So basically, your compact
bulbs, those little corkscrew top ones you may have seen, those are going to last you on average about
6 to 8 months. Your linear tubes will on average, last you about 12 months. And then with
your mercury vapor bulbs on average, you're going to have an output anywhere from 12 to 14 months.
And then above that, would be metal halide which we don't really, uh, use that often. It's a specialty
application, but you can research more on that if you like. Uh, and the way that we test these
bulbs, is we use what's called a radiometer, um, and what that is doing is basically measuring microwatts
per centimeter cubed, and generally for most basking reptile species you're going to want a range
as low as 25, but really you're probably going to want between 25 to 50 micro watts as your ideal UV
range. So when we're mounting this in our enclosure, we can, you know, use a radiometer. Obviously you
may not have that at home, but what at the bottom range you're going to have the lowest output, and
then closer and closer to the bulb ,you're going to have the highest output. The next thing is when
we're mounting our mercury vapor bulb, it's very important that it's kept in a vertical position.
A lot of folks will either try to put it on an angle, just to save space in their enclosure,
and obviously with this type of bulb you would never want to mount it sideways, like your tubes.
There's two reasons for that. Mostly, uh, the components in here don't operate in a linear
state, and the second reason being the longevity of the bulb is greatly decreased if you mount it
at an angle or anything sideways like that. So it's always best to hang your bulbs, uh, straight up and
down vertically. Another tip I would also recommend is, when you get your new mercury vapor bulb or
box at home, you take out your bulb, you want to keep a record or write down the date that, uh,
you purchased. And then we usually like to check in an interval, probably around the 6 to 8 month
mark, you can bring your bulb in, um, you know, have it checked, we can make sure the output's still
good, and then, uh, beyond that, once you're past that 12 month mark, I would definitely have it tested
in pretty regular intervals. Typically your maximum life span on this bulb is going to
be about 14 months on average, you'll see that 12 to 13 month range. So these bulbs will often last
longer than that 12 to 14 month range, however that's going to be just your UVA, which is your
visible light spectrum, it's not going to be any of that UVB that you need for your animals
bones. So even if your bulb is still functioning, you're still seeing light, that doesn't necessarily
mean that your animal's getting the necessary UVB it needs. So when we mount our mercury vapor bulb
in our enclosure, there's a couple of ways we can do it. Um, a lot of times you know with a certain
wattage bulbs we're obviously going to need those bigger fixtures. Um, a lot of folks will use a deep
dome fixture, um, I personally prefer to use a wire light fixture, and there's a couple reasons for
this on the larger size bulbs. On the 80 watt, the 125, you could probably get away with the deep dome,
but for the 160s and the 125, we definitely recommend using a wire light fixture. The
reason for that is, inside the deep dome there's a metal housing that basically houses all that
heat that this bulb produces, and because this is the all-in-one bulb it's not only producing that
UVB, but it's also producing that heat, uh, and in the higher wattages like in the 160 watt and the
125 watt, you're going to find that that reflector dome on the inside is containing a lot of that
heat. Uh, there's two things with this. So it can cause those, uh, auto shut offs basically, the safety
features to activate, simply because those little reflector domes hold in a lot of heat compared to
your wire light fixture, where it's just going to let all that heat radiate out into the room.
Uh, and it does really radiate a little bit of heat, but it's not enough to sufficiently
heat, you know, a room up, you know, anything like that. Hope you guys had a lot of fun, uh, learned
a lot of information about mercury vapor bulbs watching today. If you have any questions, you
can always check out our website, drop by our store, or give us a call. Thanks and have a great day.