have become more popular as pets, a plethora of products have hit the
market all designed to thin out the reptile owner's wallet. Many do not
do what they are advertised as doing and, for some, there are already
less expensive alternatives available.
the right type of heat to a reptile is just as important as the temperatures
you provide. Reptile vets, biologists and an increasing number of experienced
herpetoculturists are all saying that that best source of heat is through
an overhead radiant source, not by a hot rock or heat tape. So, when
confronted with a shelf full of pretty boxes of light bulbs produced
to attract your attention, how do you know which one to select for your
reptile? Here are a few things to keep in mind...
bulb can be used for daytime heating...even the bulbs you use in your
own lamp fixtures. The wattage you need will depend on what it takes
to do the job. The higher wattage bulbs throw out more heat and so can
be used a little farther away from the animal than lower wattage bulbs.
Make sure the light fixture you use is rated for the wattage you end
lights may also be used for daytime heating - they are just more expensive
than regular incandescent bulbs. Some may be coated to affect the color
of the light produced - this may alter the way your eye perceives your
animal's color and the way your reptile's eyes perceive the things in
its environment. It is important to note that the "neodymium"
coated lights do not produce anything but a pleasantly tinted
light. They do not produce any ultraviolet B wavelengths.
/ Silvered Reflector Lights
Spot lights/Silvered lights/Floodlights are just lights that are shaped
and backed with a non-light emitting film so as to focus their light in
a specific direction. Many
of these lights are intended for use in recessed fixtures ("cans")
so that they are cooler on the sides so that less heat builds up in the
Some are high wattage, suitable for use for daytime heating. Some, such
as those used for exterior landscaping lighting, are low wattage and so
produce much less heat.
design and coating on spots/floods limits the width of the area they cover.
Putting a regular household incandescent into a reflective dome-type
light fixture disperses more light and heat over a wider area.
lights, such as those used in the food service industry to keep hot food
warm until it is served, may be used for daytime heating.
for Nighttime Use
time use, you cannot use a white or any bright light. Doing so
causes disruption of the animal's sleep cycles, even if it appears to
be sleeping (remember that sleep is comprised of different types of cycles
which alternate during the course of the sleep session - bright light
disrupts deep sleep and can result in chronic stress and depressed immune
function and behavioral abnormalities). Nocturnal reptile light bulbs
produce a dim light. They are generally available at higher wattages than
the regular decorative red, green or blue incandescent lights you can
find at hardware and lighting stores.
spectrum" lights which look like incandescent light bulbs are incandescent
light bulbs and so are good only for producing heat.
They do not produce any UVB. Tungsten filament technology
cannot produce UVB. The use of the term "full spectrum" is grossly
misleading. Any pet store that tells you they produce UVB is either completely
ignorant or lying to you to make a sale.
with Mercury Vapor Heat/Light/UV Products
are mercury vapor and metal halide lights which produce both heat and
UVB. Unfortunately, they may be dangerous to your reptile. They put out
very high levels of ultraviolet wavelengths requiring them to be turned
off when you are near them and/or needing to limit their time in use with
the reptile. (For my take on products such as the ActiveUV and
PowerSUN, please see my article Mercury
Vapor Lamps: Are they suitable or safe for typical home use?) It is
safer, though more cumbersome, to use a heat source and a separate UV
fluorescent tube if you cannot assure your UVB-dependent reptile access
to sufficient sunlight on a regular basis.
with Metal Halide Products
halide products also produce visible light and ultraviolet A and B. However,
they produce an excessive amount of UVA, which can cause skin and other
cancers. Metal halides produce less UVB - less than Zoo Med's reptile
and iguana UVB-producing fluorescents. Because of the danger to humans,
many of these products contain shields which filter out the UVA and UVB...so
much so that they can end up producing too little UVB for use with reptiles.
Emitting Heat Sources
Ceramic Heating Elements (CHEs) are non-light emitting ceramic units
embedded with heating elements. They get extremely hot but disperse heat
over a very narrow (15" in diameter) and shallow area. 60 watt CHEs
range is 8" down; 100 watts CHEs is 10" down, 150 watt CHEs
is 12" down, and 250 watts goes 14" down. They are not effective
in heating large enclosures...and the lowest wattage ones may be too much
for small enclosures so must be used with a rheostat or lamp dimmer switch.
It is imperative that CHEs only be used in porcelain light sockets as
the amount of heat that they throw back is enough to melt the plastic
light sockets in most clamp light fixtures. If you can't find a porcelain
socket in the hardware department of stores, head to a feed & grain/ranch
supply store and look for a brooding lamp fixture. Made to provide heat
for incubating eggs and keeping chicks warm, the domes of these fixtures
are larger than the hardware domed clamp lights, the clamps are often
stronger, and they often can handle more watts than the smaller hardware
These are suitable for
providing gentle under the tank or on the bottom of the tank heating.
They cover a wide surface area of the tank floor and may be sufficient
to warm temperate snakes during the day and night and provide night time
heat for diurnal lizards. When used with diurnal reptiles, however, they
should always be used in conjunction with overhead radiant basking
heat. Thermometers need to be used to assure that the proper temperature
gradients are being attained and maintained. These pads, which include
in-line three-way heat settings, are self-contained, easily moved around,
and can be safely cleaned and disinfected as needed.
These are expensive and
less "convertible" than the people heating pads. Once they are
stuck on to the bottom of the tank, they cannot be easily removed, and
once removed they cannot be safely used. They cannot be cleaned and disinfected
as water can seep under the pad. They do have multiple heat settings,
but because they are glued to the tank, the tank can not be moved away
from it to provide more of an air space to use to dissipate the heat.
This is tape that was
developed for use in plant nurseries to heat large flats of seedlings
and to wrap around water pipes to prevent their freezing. They are not
UL approved. Make a mistake in how you do the installation (which requires
wiring them to electrical cords and light switches or rheostats) may result
in fires or smoke outs...which has been known to happen even when they
have been installed by licensed electricians.
white light can be used for daytime lighting and heating. Nocturnal reptile
lights and dark decorative red, blue and green incandescents provide dim
lighting that will not disturb the sleep of diurnal (active during the day)
reptiles and isn't stressful to nocturnal reptiles. Diurnal reptiles need
a bright white light during the day if the ambient room lighting is dim
or the only other source of light is a UVB producing fluorescent.
Lamp/Ceiling Fixture Bulbs
Any light bulb you use
in your own table lamps or incandescent ceiling or wall light fixtures
to provide light for your home can be used during the day to provide bright
white light and heat for your reptiles. The only difference between the
incandescent bulbs you buy in your grocery or hardware store and the more
expensive bulbs marketed for reptiles at the pet stores (besides the price
tag!) is that some of the reptile bulbs have been "color corrected"
to remove the yellow wavelengths; all this does is alter the apparent
of the reptile to you, and will affect slightly how the reptile perceives
its environment. However, when using a household incandescent in conjunction
with a UVB-producing fluorescent, yellow wavelengths will be provided
and, more importantly, UVA, into which spectrum many reptiles can see.
These are simply incandescent
light bulbs that have been treated to block part of the visible spectrum.
They produce heat, and may affect somewhat the colors you see
when looking at your reptiles. As stated above, they do not produce
UVB. These bulbs are considerably more expensive than household lights.
My recommendation is to use household lights during the day, spending
the money you save on nocturnal reptile lights for night time heating
if you cannot find household red, blue or green incandescents of high
enough wattage for your needs. A word of warning: ESU makes the "rare
earth" "black phosphorous" nocturnal lights. They are nice
as they come in a good choice of wattages and produce a dim purply-blue
glow that won't disturb your reptile nor you if your reptile is in your
bedroom. However, these bulbs regularly burn out within a few months of
purchase. Most people don't bother to complain to the manufacturer or
even the pet stores, so this problem just continues on and on. Please:
if you haven't dropped it and have used it properly,
installing it in a light fixture rated for the wattage, complain
to the manufacturer and pet
(Ultraviolet B) and UVA (Ultraviolet A)
The only lights
that can safely provide these two critical wavelengths to your diurnal
reptiles are the UVB/A producing fluorescents made for the reptile pet
trade. (Note: for the problems associated with the use of screw-in compact
fluorescents, please see my comments in the UV Table article referenced
and plant "grow" lights-incandescent and fluorescent-do not
produce UVB. Tanning salon fluorescents, tubes made for phototherapy for
humans, germicidal UV tubes, and mercury vapor lights, all of which produce
UV, do so at levels that are unsafe for the reptiles and their
keepers. Many of these produce very high levels of UV and are designed
to be used for very limited periods of time and require that
protective eye gear be worn (and to my knowledge, despite the availability
of ponchos, sombreros, and motorcycle jackets, no one has made UV resistant
goggles for iguanas yet....).
these lights also produce UVC, that range of wavelengths (< 290 nm)
known to cause immune suppression and cancer in humans and animals. UVB
producing fluorescents that produce a decent amount of UVB (1-5%) aren't
very bright (have lower CRI) - bright UVB producing fluorescents (high
CRI) do not produce much UV; that is a tradeoff required by the technology
itself. So, when using a UVB producing fluorescent, you should be using
a white light emitting incandescent as well - this will give your diurnal
reptiles both the UV and the bright light they need. A list of UVB producing
fluorescents can be found at the end of the UV
Table article in the Ultraviolet section Captive
Environment page. See also the new article by William Gehrmann, Reptile
Lighting: A current perspective which includes a table of tubes.
- Color Rendering Index
Those of you
who are bothered by low interior lighting or who get somewhat grumpy or
depressed on cloudy days, but who find life wonderful indeed on bright,
sunny days or in well lit rooms, are responding to the difference that
low CRI and high CRI make - the higher the Color Rendering Index (CRI),
the better things look to us.
reptiles alike see into the visible light range (400-700 nanometers).
Reptiles and many other animals (but not humans) can also see into the
UVA range (320-400 nm). UVB producing lights also produce UVA. UVA subtly
affects the way things look to a reptile, from the color of their food
to the color of their bodies. To us, male anole dewlaps look reddish -
to another anole with sufficient UVA, however, they are brilliant, radiating,
flaring red. The tongue of a blue-tongue skinks looks, to us, like the
skink has been eating a basket of blueberries. To another blue-tongue
skink, however, the tongue is a bright, fluorescent, day-glo pink. Failure
to provide UVA to diurnal reptiles can causes subtle stress by altering
the reptile's perception of its universe and how it responds to it. This
can be crucial if you are thinking about breeding them or keeping them
around for the length of their natural lifespan...
NM), of course, is critical for the formation of the chemical which ultimately
is transformed by the animal's body into vitamin D3. D3, as the articles
on calcium and metabolic bone disease tell us,
is critical for the proper uptake and metabolization of calcium in the
Some of the long fluorescent tubes come with a twist in them. This serves
to increase their surface area and so they are brighter (and presumably
emit somewhat more UVR) than the straight versions. These twisted UVB-producing
fluorescent tubes, such as DuroTest's PowerTwist,
are fine to use for reptiles. Compact UVB-producing
fluorescents, however, are inappropriate for most herp enclosures
as the UVR disperses so quickly over distance that larger reptiles receive
too little UVB and will develop MBD. These compact lights, which are attractive
as they screw into an incandescent-type fixture and take up less space,
may be safe for reptiles whose adult size is small, say, no larger than
the smaller anoles. Note: not all compact fluorescents are intended
to produce UVR for reptiles. If you are buying one specifically to try
on a small reptile in a small enclosure, make sure you buy one made specifically
for this purpose.
Points to Remember When Setting Up Your Enclosure
your incandescents used for heat and your fluorescents used for UVB/A
at the same end of the enclosure. You can certainly use a fluorescent
tube that extends partially or completely down the full length of your
enclosure, but if you are using a short tube, be sure to house it adjacent
to the basking light. I find that too many people are putting the fluorescent
at one end and the white basking light at the other.
you need to place them adjacent to each other is that the bright white
light will attract the reptile to the warmest area so it can bask. It
will spend most of its time during the day there, and while there, will
be exposed to the UVB and UVA produced by the fluorescent. As it thermoregulates,
it will move along the gradient of heat, but always going towards the
bright white light to warm up. If provided with a non-white light emitting
heat source on one end of the enclosure, and a cool white light at the
other, such as that emitted by fluorescents, the reptile will elect to
sit under the white light because it is attracted to the light. Thus is
will fail to attain the temperatures it needs to ensure proper digestion
and good health.
UVB Fluorescents Regularly
a period of time, the amount of UVB (and, presumably, UVA) emitted by
the fluorescents decreases to the point where it will fail to provide
sufficient UVB for vitamin D formation. This degradation occurs long before
the bulb "burns out" - ceases to produce any visible light.
Unfortunately, there is little data to indicate just how long the various
bulbs produce sufficient levels of ultraviolet wavelengths. Experienced
herpetoculturists change these tubes every 6-12 months. Mark your calendar,
or pick a particular day of the year (your birthday, New Year's day, etc.)
on which to do it that will be easy to remember.
the Distance Between the Reptile and the Light
away from the fluorescent tube your reptile is, the less UVB it will actually
get. The drop off is dramatic: at two feet away from the light, the reptile
is getting only one-fourth of the UV it would get at only one foot away.
It is recommended that the light not be any further than 18 inches (46
cm) from the reptile, and preferably much closer, such as 10-12 inches
(25-30 cm). This may call for some creativity on your part if your reptile
is housed in the typical glass tank sold by most pet stores, or is set
up as a free roamer. In custom built enclosures, the lights can be securely
ceiling-mounted in the enclosure, with the basking areas set up the appropriate
distance beneath them.
snakes need ultraviolet B wavelengths, too?
snakes evolved from lizards some 120 million years ago, they also evolved
other ways of dealing with the issue of calcium metabolism. Snakes are
carnivores, consuming, depending on the species, a variety of vertebrate
and invertebrate prey from which they obtain the D they need. There is
some speculation that snakes may need some UVB given the habits of some
crepuscular and nocturnal ones in the who regularly emerge before sunset
and "bask" in the setting sun. However, these same species have
been kept for decades in solid enclosures indoors where they are not exposed
to any more UVB than what little permeates through window glass and the
glass of their enclosures.
is some evidence that some reluctant feeders may be enticed to eat when
exposed to a UVB/A light for sunlight for a while (during day time hours
for up to a week). This has worked with corn snakes that I know of. I
don't know the mechanism at play - maybe they are responding to the UVA
and so things look more appetizing to them. Care must be taken
when exposing your snake to sunlight. Too many owners have found out the
hard way just hot hot it gets inside a glass tank set outside on a sunny
day - and just how quickly their snake becomes toast. Make sure your snake
has a cool area to retreat to, and that it is not exposed to sun during
the hottest parts of the day, nor left unattended when exposed.
When using heating pads for free-roamers or on shelves installed
in enclosures, install a small hook (such as a cup hook, found at hardware
stores and in the hardware aisles of grocery stores and stores such as
Long's and Walgreen's) on the underside of the shelf. Run the heating
pad's cord through the hook so the full weight of the cord (including
the on/off switch) isn't pulling on the pad.
cords that are installed in an area where there is or may be water should
be set up so that they have a drip loop. A drip loop is simply a section
of cord that hangs lower than the electrical outlet into which it is plugged
so that, if water should come into contact with the cord and run down
the cord, the water will run to the lowest level and drip off - and not
go into the electrical outlet. In the case of cords with on/off switches
or transformers, the drip loop should be situated between the appliance
and the switch/transformer.
more safety information, please see the Fire
looking at what you need to make sure your reptile is getting what it
needs to have the best chance of health and behavior, you need to consider
lighting and heating as having three distinct but interrelated functions:
heating (day and night), metabolism, and behavior.
it is critical to provide the proper lighting and heating for diurnal
reptiles, so too is it important to provide the proper lighting and heat
for nocturnal ones....and that generally means no light or very dim light.
Using a white light to heat a nocturnal reptile at night is just as stressful
to it as using the same light to heat a diurnal reptile at night. We must
tailor the equipment used to the animal's evolved requirements/needs.
- Not Simply A Matter Of Watts