Is Lighting Important For Bearded Dragons?
The topic of bearded dragon heating and lighting is quite daunting when you first start researching the best for your bearded dragon. Getting the heating and lighting right in their vivarium is extremely important for a number of reasons;
- Correct amounts of UVB (Ultraviolet B light) is important to prevent Metabolic Bone Disease. D3 supplements are shown through scientific studies to NOT prevent MBD – UVB is the only prevention for it.
- Infrared / heat is required for bearded dragons to digest their food properly.
- Heat from a basking lamp is required to give Bearded Dragons their energy to move. This is because they’re a cold blooded reptile and cannot generate their heat internally like mammals do.
- Lighting guides their metabolism and brumation cycles.
- UVA is an important component of light for bearded dragons to see properly.
If you don’t have the right lights in your vivarium, your beardie is not going to thrive – so the right lights are extremely important for the health and wellbeing of your beardie.
Because Bearded Dragons originate from the dry, arid areas of Australia, they require high levels of UV light – much higher than many other reptiles. The sun in Australia is particularly harsh – and shines for pretty much all of the day time with minimal cloud cover to obstruct it. For humans this can be a big problem as we tend to develop skin cancers (melanomas) when exposed to too much of it. But bearded dragons have evolved to survive and thrive in this environment and so they require similar amounts of it in captivity.
Which UVB Lights should I use?
There are three types of UV bulb that are available. They are Mercury Vapour bulbs, Fluorescent Linear Tubes (strip lights in the UK) and Compact Coil Bulbs. These latter bulbs, the compact coil bulbs were introduced as low energy light bulbs before LEDs were manufactured. Compact coil bulbs are not suitable for use with Bearded Dragons as they don’t provide enough UVB – and the UVB output they do provide degrades significantly within a couple of months – rendering them useless in a bearded dragon vivarium.
The lights we use in our vivariums can all be found in our article about What Equipment Do I Need For My Bearded Dragon
Mercury Vapour Bulbs
These tend to look a lot like spotlights, and they concentrate the UVB into a small area – but they do provide a LOT of UVB into that specific area. They can be used above an area where the bearded dragon spends time basking as they tend to provide a similar amount of UVB as the sun, provided the beardie is actually within the lit area.
MVBs should generally be placed about a foot ( 30cm ) above where beardie will spend their time basking as this provides the optimal amount of UVB within that radius. The distance does vary depending on the manufacturer of the lamp though, so it’s worth being guided by the instructions for siting these.
MVBs tend to be more suitable for a larger tank, as the dragon will need to be able to move in and out of the lit area and therefore moderate the UVB it gets rather than sitting in it all the time. This is because although bearded dragons will bask in the sun in their native habitat, they also spend some time in the shade too. Which is where the Fluorescent Linear Tube comes in. MVBs can have the potential to overdose your bearded dragon because all the UV light is concentrated in the one area and is extremely strong in that area.
MVBs are not suitable for use with dimming thermostats.
Fluorescent Linear Tube (Strip Light)
These provide similar amounts of UVB to the equivalent of a shaded area in the desert. These come in various sizes and with varying UVB outputs expressed as a percentage. Generally speaking a bearded dragon vivarium should be at least three quarters the length of the vivarium. This means that for a tank that is 4 feet in length, you’ll need a UVB fluorescent tube that is at least 3 feet ( 36 inches ) in length. It should be positioned towards the basking end.
Which Type of UVB Strip Light Do I Need?
The higher the percentage the better for a bearded dragon enclosure. The UVB output is expressed as a percentage and common values are 8, 10 and 12 percent. The 12 percent rated tubes will put out more UVB than the 8 and is the recommended value for bearded dragons. This is due to the fact that, as mentioned above, bearded dragons have evolved to require a lot of UVB.
Be aware though, that a 12 percent lamp that is dim might put out less UVB than an 8 percent lamp that is brighter – so check to make sure the amount of UVB exposure is at least 13 microwatts per square centimetre across the entire tank, with additional UVB at the basking spot. ZooMed have produced a paper on this, following extensive research into the area. It’s available as a PDF and can be read here.
Where Should The UVB Be Mounted?
Just to confuse matters even further, there are two types of fitting for a UVB strip light. There is T8 fitting (common in the UK) and T5 fitting (common in the USA). Where it should be mounted and what type of fitting is best, is determined by the type of vivarium you have.
You didn’t realise bearded dragon heating and lighting could be quite so complicated did you! It’s OK, we’ll get you through it.
In the UK, most vivariums are made from wood. So it stands to reason that the UVB lamp is going to have to be mounted inside the vivarium – on the ceiling. UVB Strip lamps that are mounted on the inside of the vivarium should be the T8 fixture as these provide the optimal amount of UVB for this type of mount. Consider getting a reflector as well to help bounce some of that UVB down onto the floor.
In the US, most vivariums are glass all round with a metal mesh covering the top. This makes it harder to keep the tank warm and also reduces the amount of UV light that reaches the floor of the vivarium. So for this reason, if you’re mounting your UVB strip light outside the tank above the mesh you’ll need a T5 High Output (HO) variety.
To confuse things further, you cannot place a UVB light on top of glass. Mesh is OK, but glass is not. UVB cannot penetrate glass.
Rule of thumb: Mounting inside the vivarium = T8, mounting outside = T5 HO.
Further information about which Fluorescent Light to get for best results can be found in our article, What Equipment Do I Need For My Bearded Dragon?
How Long Should I Keep The UV Lights On For?
Most herpetologists specialising in bearded dragon heating and lighting recommend that at least 10-12 hours of UVB light is required to maintain the health of your bearded dragon. The lower number is recommended during periods of brumation and 14 hours can be a good number during the summer time as this is the level of light the bearded dragon would be used to in the wild.
Bear in mind that the mercury vapour lights and strip lights cannot be dimmed, whereas the basking lamp (which also provides heat and is detailed below) can be.
We recommend the use of an electrical timer for the lights as they can then be switched on and off as appropriate without you needing to be there to do it physically. You can adjust the timers to vary the amount of time the light is on for depending on the season and whether your bearded dragon is going into brumation.
How Often Do The Lamps Need Replacing?
This depends a little bit on the lamp itself, the mercury vapour lamps generally should be replaced once every 6 months, whereas the fluorescent tubes will generally last around a year.
Be aware that you should replace the lamp even if it appears to be functioning properly. This is because the amount of UVB that is put out by these lamps degrades over time and you won’t be able to tell if this is happening unless you have a UVB light meter. If you do then you might be able to get more time out of your lamps because you’ll be able to tell how much they’re putting out. But UVB light meters aren’t cheap so it’s probably better to just rely on changing the lamp regularly.
Do Bearded Dragons Require UVA Light Too?
Yes – they most definitely do. Studies have shown that reptiles (and birds), unlike humans, have 4 light receptors in their eyes. Humans have three ( red, green and blue ). So reptiles can actually see light that humans cannot. Without UVA light, bearded dragons become partially sighted, at least from a colour perspective. Imagine your life if you could not see blue colours (some people actually can’t, although this blue colour deficiency is quite rare in humans).
Fortunately the strip light will provide UVA light too and although it isn’t essential for the calcium metabolism it’s certainly going to impact on your bearded dragon’s wellbeing if they can’t see properly around them. It could even impair their ability to hunt for their live food.
Should I Have A Red Light For My Bearded Dragon?
No. Although many pet shops will try to sell you a red light for your tank, bearded dragons don’t need red lights and some believe it may even be detrimental to them. Bearded dragons don’t require any light overnight (although they will still require a suitable temperature overnight) and it’s believed that red lights kept on overnight can impair their sleep pattern. You wouldn’t like to be sleep deprived due to too much overnight light and beardie won’t either. Given that bearded dragons have this extra ultraviolet sensor in their eyes it’s possible that too much red light may interfere with the way they see.
Do Bearded Dragons Require Heat Lamps?
Yes. These are usually referred to as a ‘basking lamp’ and they’ll put out plenty of UVA as well as the heat required for your beardie to have enough energy to hunt and play as well as digest its food properly. The basking lamp should provide enough heat to warm the entire tank, unless the tank is huge. If it doesn’t then you can add a ceramic heatlamp to the enclosure to warm it up further if necessary.
Basking is an activity your beardie will enjoy and enables them to digest their food properly. If the temperature in the basking spot isn’t warm enough, beardie won’t get enough heat from the surroundings to digest their food. Undigested food can lead to significant health problems ranging from fermentation, infection, impaction and metabolic bone disease.
The basking spot temperature should be between 38 degrees celsius to 43 degrees celsius ( 100F – 110F ), measured at roughly the height of the bearded dragons back, at the place in which they bask. For this a digital thermometer with a probe that can be placed appropriately is the best way to measure it. Adult bearded dragons don’t need quite as high temperatures as babies and juveniles, so you can add a couple of degrees to those numbers if you’re housing babies.
But, bearded dragons don’t need this high heat all the time, so the basking spot should be placed at one end of the tank, with the other end of the tank left cooler. The cool end of the tank should be between 22 degrees celsius and 30 degrees celsius ( 72F – 85F ).
Having this temperature gradient throughout the tank enables your bearded dragon to choose for themselves which temperature they want at any given time.
Overnight temperatures should remain around 16-20 Celsius ( 60 – 68 Fahrenheit ).
Bearded Dragon Heating At Night
Bearded dragons should have NO lights on overnight. They’re desert dwelling animals and would only ever have enough light to see from the moon. But they’re also diurnal creatures, meaning they are awake during the day and asleep at night unlike some other reptiles.
Temperature wise, most houses probably won’t get cold enough overnight to require any bearded dragon heating at night – but if they do then a Ceramic Heat Emitter (CHE) should be used to keep the temperature just above 16 degrees Celsius. This is approx. 60 Fahrenheit.
This lower temperature gives the bearded dragons time to rest and sleep properly and is important as this helps to mimic their natural environment. The environment bearded dragons come from can get quite cold overnight.
What Are Ceramic Heat Lamps?
These are devices that are, unsurprisingly, made of ceramic and fit into a standard lamp holder, but they produce no light at all. Their sole purpose is to provide heat. These can be used to keep the temperature of the vivarium to within the overnight range if your house gets colder than that overnight. In this way you don’t need to keep your whole house heating running overnight just so beardie is comfortable.
They can be attached to a thermostat so that they only come on if the temperature starts to approach the colder end of the range, such as 18 Celsius. In this way, the ceramic heat lamp will only come on overnight since the basking lamp will likely be providing the heat during the day, but the ceramic can keep things warm overnight.
Ceramic heat lamps generally last longer than heat lamps, so the ceramic heat lamp can be a good backup if you suddenly find that a basking lamp has blown and you don’t have a spare. Your Bearded Dragon will survive for a couple of days while you find a new basking lamp to replace the blown one with.
Light And Temperature Quick Reference
- Strip lighting required across the entire vivarium to provide UVB – 12% is recommended ( 13 micro-watts per square centimetre ).
- 10 – 14 hours per day of light required, adjusting downward if Beardie is heading into brumation.
- T8 sized strip lighting must be inside the vivarium, not outside. T5 is used for outside mounting on a mesh.
- 38 – 43 Celsius, 100 – 110 Fahrenheit at basking spot.
- 10 – 14 hours per day of basking light too.
- 22 – 27 Celsius, 72 – 80 Fahrenheit at cool end.
- 16-20 Celsius, 60 – 68 Fahrenheit overnight.
- Ceramic heat lamps overnight, no basking light or UVB strip.
More information about which lights, ceramic heatlamps and UVB lamps along with controllers and accessories for measuring the temperature can be found at Which Equipment Do I Need For My Bearded Dragon? including links to the specific items we use ourselves.
Hopefully this post has been helpful for you to pin down why lighting is so important for the health and wellbeing of your bearded dragon. I hope it’s also been useful to help you figure out which types of lighting you’ll need if you’re just setting up your tank.
If you’ve still got any questions about Bearded Dragon lighting requirements though, please do ask a question below. If you like you can also join our Facebook Group – Bearded Dragons Rock and hang out with us and ask us anything you like.
Thanks for reading, leave a comment with any suggestions or feedback and enjoy your bearded dragon 🙂