All right, so when it comes to UVB there's several different things that
you need to take into consideration. The first is the strength of the UVB and
then the second is the type of UVB bulb. So I'm going to start first by discussing UVB
strength. There's generally a few different strengths you're gonna see on
the market. There's what's called a 2.0, which is reflected here with the natural
light, it's a formerly a 2.0 UVB. Then there's a 5.0, which we have here, the 5.0
or the Zoo Med version 5.0. Then there's the 10.0 which you can see
here is a Zoo Med 10.0 and Exo Terra has a nice small print 10.0.
And then there's the newer, what I call a 15.0 which is just made by Exo
Terra right here. So what does all that mean 2.0, 5.0, 10.0, 15.0? What it really
means is a UVB penetration depth. So that penetration depth is more important than
what it says on the box. Your tropical bulb is a 5.0, your desert bulb is a
10.0. However, that does not necessarily mean that this is only for
desert and this is only for tropical. What it means is it's a reflection of
the UV beam penetration. So backing all of that up, a 2.0 is going to give you 3
inches of UVB penetration max, and that's without a screen lid in place. Once you
put a screen lid in place you're gonna cut about half of your UVB penetration.
All right so this is a radiometer, this measures UVB output in micro watts per
centimeter square. Typically what you want to see for a desert species is a
range of 25 to 50 micro watts then for a tropical species we go for 12 to 25
micro watts. So you can see when we get right on the bulb once you get in there,
you can see how high that's reading. This must be a fairly new bulb and as we get
further away from the bulb, notice it comes down a little bit lower. So the
further away we get, the lower it gets, and that's why the UVB penetration is so
important. Now notice this we're sitting at about 400 micro watts, I'm gonna put a
screen lid in its place now, I want you to see the big difference. So now right
about the same height, it's shaved about a hundred micro watts off so the screen
lid does matter. Furthermore, something I want you all to
see, we get this a lot from people, a lot of times people will say, "Well my tank is
in a window doesn't that count for UV?" Glass filters out a hundred percent of
UV light. So today we have a very overcast day, very low obvious sunlight
coming through, but I want you to see this. If I point this radiometer through
the glass you can see we're getting nothing. Even on an overcast day,
now there's UV coming through. Now again it's minimal, but we're also in January
and it's very overcast, but the point I'm making is that glass filters out nearly
a hundred percent of UV. So putting your tank in front of a window will not give
you the UV output that you need. In fact, you'll be twice as bad, because you have
the glass from your tank that's filtering the UV and the glass from the
window. So this guy right here is virtually useless
the UVB output, it's primarily used for plant growth or as an antimicrobial.
In other words, it'll help keep down molds and bacteria in the tank. Your
5.0 bulb is typically going to give you 12 inches maximum UVB penetration, and
again that's without a screen lid. Your 10.0 is going to give you 16 to 18
inches max penetration, and then your 15.0 or your UVB 200, this will give
you about 20 to 22 inches max penetration.
Now the reason all of that is important, let's just say that we have a tropical
animal that's 16 inches away from the bulb, we're gonna use the 10.0 or
the desert UVB. So this is really just kind of a marketing word right here,
desert, what we're really looking at is that UVB penetration. On the flip side,
let's just say you have a desert animal that's three inches from the surface of
the bulb, you may be able to get away with the 5.0
because this gives you 12 inches in UVB penetration. All those synthetic
UVB bulbs are not nearly as strong as the sun, they too can be too powerful for
the animal, because the animal is exposed to them all day, versus outside in the
sun that they're able to hide, you know, basically for part of it.
So now that you know that, your difference between your 2.0, 5.0, 10.0 and 15.0, now we can look at a few other variations of the UVB bulb.
The next variation is the mercury vapor bulb. We have the Solar Glo line right
here by Exo Terra, and then the Power Sun bulb right next to it by Zoo Med. So
there's two components to this bulb, first is the UVB penetration, so as I
explained on the 5.0, 10.0 and 15.0, these guys are going to give
you three feet of UVB penetration regardless of the wattage. So notice we
have 80 watt, 125 watt, 160 watt in Exo Terra, our Zoo Meds go 80, 100, and 160. UVB
penetration is the same on all three of those three feet. So when we're looking
at that now we have to look at the size of the tank or the height of the tank. So
say you have a bearded dragon and a tank that's 24 inches tall, you're gonna need
one of these mercury vapor ones, these guys just aren't going to cut it.
Typically like a bearded dragon in a 55, although it's 21 inches tall, we always
go with mercury vapor to get the adequate UVB penetration. So the
difference in these bulbs is the wattage or the heat output.
Mercury vapor bulbs are an all-in-one bulb, as you can see right here they are
a combo between heat and UV. So your difference on the wattage is how hot the
bulb is. Typically a 160 watt on a 40 breeder tank will give you a 95 degree
hot spot, so that's what we tend to use for bearded dragons. The 125 watt on
a 40 gallon tank will give you maybe an 85 degree hot spot on the ground, but in
the tree it might give you a 90 degree hot spot, so that's really good for like
water dragons. Your 80 watt bulbs are gonna be if you want to put a mercury
vapor bulb on like a 20 long or something. So we've now covered our
compact fluorescents which are these guys, we've covered our mercury vapors
which are these guys, but there's still a couple other versions on the market. Next
we have the metal halide which you see right here is the Power Sun H.I.D by Zoo Med.
Now the metal halide is a very unique bulb in that it will not plug into a
standard fixture, it has to have its own separate ballast which is built into
that hood. Those bulbs will give you six feet of UVB penetration so this
could be critical in a very large enclosure like a full room enclosure
for a green iguana, which we keep our green iguana in. Anything that's gonna be
very tall and very large is where that would come into play. From a heat output
it's gonna be very similar to the 160 watt mercury vapor, that's only a 70
watt bulb but metal halides are very hot, so at about 18 inches from the surface
of the bulb to get about the 95 degree hotspot. What you get more than anything
is that UV penetration. So typically if you're using that bulb you're still
going to need supplemental heat, but you'll get
the penetration you need. Next we have our T5 linear fluorescence and our T8
linear fluorescence. So over here T8 is kind of the thicker style bulb, let me show you what that
looks like. So this is a T8, if you look at the thickness of the bulb. The old bulbs you
used to see overhead were T12, that's really thick they're about that big, your
T5 bulbs are significantly thinner. So there's a T5 versus a T8. So what's
going on here with the different bulbs is simply energy efficiency. The T5 bulb
is gonna run at a much lower wattage than the T8 bulb will, and therefore
it'll be a little more energy efficient. So like this right here is a
12 inch bulb at 15 watts, this is an 18 inch bulb at 15 watts, so energy
efficiency strictly. Now on the linears, the main bulbs that you're going to see
again are 2.0, 5.0, and 10.0. The 2.0 is really starting to go away and you're
primarily seeing 5.0 and 10.0. Your UVB penetrations are the same. Your 5.0 is
gonna give you that 12 inches of penetration from the surface of the bulb,
where as your 10.0 will be 16 to 18 inches of penetration from the surface of the bulb.
All of that being said, the Reptisun line right here, well these are all
the Reptisun line, but uh the line that comes with the hood these have a
very high-quality reflector in them and these particular hoods come with a 5.0.
Now the 5.0 is technically 12 inches of UV penetration,
however when coupled with this hood that 5.0 will give you upwards of 20 inches
of UVB penetration, without a screen lid, so it is possible to use one of
these hoods on a 40 gallon tank with a bearded dragon and get the UV that you
need because the reflector is so high quality. So now that you understand the
difference between all the strengths, the next thing we need to discuss is how
long the UVB actually lasts. Since UV is radiation in essence, these
bulbs do expire. Once you turn them on they start to degrade and the UVB wears
out over time. So we might get a certain UVB rating right out of the box, in six
months it'll be half that strength, six months later it'll be even half that strength.
The Zoo Med bulbs are really cool in that they give you a spot on the bulb,
they give you a spot on the bulb to write the date of first use. So let me show you what
this looks like. So first use date, replace yearly. Now here's the thing with
that, these don't generally last a year. We have a radiometer here where we can
measure UVB output on the bulbs, and typically what you're gonna find is your
compact fluorescents, which can be this style or this style, are only going to be
good for about six to eight months. So write the date on there, in six to eight
months bring it to us and let us test it. If you don't live locally, figure within
six to eight months the UVB is going to be shot and then it's time to replace
it. Mercury vapors, they typically will last about 12 to 14 months before
the UVB is shot. That metal halide, we ran one for two years and the UVB was still
good, so I'll throw that out there. As far as the linears go I would say these
guys are pretty close to a year. Zoo Med is a real high quality bulb, but
typically you'll get about a year out of it. So just because your UVB bulb turns
on and appears to be working doesn't mean that it's actually outputting the
UVB penetration or the UVB output in a sense.