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Lighting Guide

Do Bearded Dragons Really Need Specialized Lights?

While setting up proper lighting for your beardie’s habitat may seem like a daunting task, in reality, bearded dragons only need two types of bulbs—a UVB bulb for mimicking the UVA/UVB radiation they get from the sun and a basking bulb for heat/warmth.

The proper amount of UVB output is especially important to desert-dwelling reptiles such as bearded dragons. This is because it helps them metabolize Vitamin D3 and calcium, without which, bearded dragons suffer from serious and often fatal illnesses such as metabolic bone disease. A proper basking light helps bearded dragons regulate their body heat, and aids in supporting many vital functions, such as digesting food and maintaining a proper metabolism.

Are All UVB Bulbs the Same?

When it comes to your beardie’s health, the answer is a resounding no! Arguably, there is nothing more important in your entire setup than a proper UVB light source.

There are two ways in which you could supply UVB—a UVB fluorescent bulb and a mercury vapor bulb.

UVB Fluorescent Bulbs

So let’s start with the most common type of bulb used for bearded dragons —a tube fluorescent.

The first thing to remember is that the UVB bulb you choose should be a tube-style bulb and NOT a compact fluorescent. Compact fluorescents do not supply adequate UVB radiation to keep your beardie healthy.

But don’t take our word for it! A scientific study carried out in 2017 at Wageningen University in the Netherlands found that most compact fluorescent bulbs marketed for reptile-use resulted in bearded dragons’ plasma concentration of Vitamin D3 to be at levels barely detectable after 120 days. A notable exception was that the Arcadia compact fluorescent performed considerably better than the rest. However, free living bearded dragons were found to have plasma concentrations of Vitamin D3 ten times higher than dragons in the Arcadia lamp study group.

Bottom line, when it comes to your beardie’s health—tube style fluorescent bulbs are the way to go.

To make your life easier and to keep your beardie as healthy as possible, there are only two types of UVB fluorescent bulbs that we recommend as the gold standard:

In a market supersaturated with different types of bulbs to choose from, why is this list so small? Simple. These bulbs have been thoroughly studied and have been proven effective and safe for bearded dragons. On the other hand, the vast majority of other UVB bulbs on the market have been linked to various adverse health effects for bearded dragons.

For example, the Zilla Desert Series and ReptiGlo have been known to cause eye problems and other health issues with bearded dragons.

Many reptile-oriented bulbs on the market do perform well with other reptile species but bearded dragons require a higher UV index (upper end of Ferguson Zone 3; maximum between 2.9 – 7.4) because in the wild, they live in hot and arid parts of Australia and bask daily under the open sun.

If you’re interested in learning more about the four Ferguson zones and testing the UV range in your bearded dragon habitat, it may be worthwhile to obtain a solarmeter. Here is one popular model

My Fluorescent Bulb is a T8, Now What?

First, without launching into a lengthy explanation regarding the various numbers and letters listed on the bulb, T5 and T8 refer to the circumference of the tube (T5=5 cm and T8=8 cm). T5 technology is newer and better suited for providing high output UVB light that your bearded dragon needs to thrive. T5 lights are stronger and brighter, and are typically mounted on top of the enclosure.

T8 fluorescent tube bulbs must be mounted inside the terrarium to provide proper UVB output, and its lower output means that they must be mounted at the appropriate distance. T8 fluorescent bulbs may perform better in smaller tanks, but in general, T5s are preferred for keeping bearded dragons thriving and healthy.

Another important difference between T5 and T8 bulbs is that T8 bulbs need to be replaced at least every 6 months to maintain proper UVB output while T5 bulbs can last up to one year. While T8 bulbs tend to be cheaper, because of the frequency with which they need to be replaced, T5 bulbs may be more economical.

Having said all this, T8 bulbs have been around for a long time so while they are not as good as T5 bulbs, they can still serve you well if used correctly.

If you feel that T8 bulbs would better suit your bearded dragon setup, these Arcadia and Reptisun bulbs are the best on the market (as far as T8 bulbs go).

So I bought the correct bulb, what fixture do I need for it?

UVB tube fixtures typically come in 24 inch size (for 22 inch bulbs), 36 inch size (for 34 inch bulbs), and 48 inch size (for 46 inch bulbs). Pick a size that will extend to cover approximately 2/3 to 3/4 of your total terrarium length. Make sure your fixture is properly sized for T5 bulbs or T8 bulbs.

Many reptile-oriented shops sell some generic T5 and T8 fixtures. They can also be obtained at some local home improvement stores, but it’s harder to find fixtures with reflectors there. The best fixtures have a metallic/silver reflector for maximizing UVB output.

We like the following fixtures from Reptisun and Carolina Custom Cages that can be purchased through Amazon.


Fixtures that fit T5 bulbs

Arcadia also sells a T5 fixture, and it comes equipped with the correct T5 Arcadia bulb.

This Arcadia fixture utilizes a teflon free technology and is free from any reflector coatings that absorb UV.

Fixtures that fit T8 bulbs

If you choose to mount your fixture inside your habitat, check out these fixtures that fit T8 bulbs.


How do I know which bulb/fixture is right for my size habitat?

The general rule of thumb is if your bearded dragon lives in a 40 gallon breeder tank (36” x 18” x 18”), then you will need a 24 inch fixture for your fluorescent bulb. If you have a 67 gallon tank (48” x 18” x 18”), then you will need a 36 inch fixture. For our recommended 120 gallon terrarium (48” x 24” x 24”), you will also need a 36 inch fixture since the horizontal dimension is the same as the 67 gallon terrarium.

Can I use a Mercury Vapor Bulb (MVB)? It’s Only One Bulb for All My Needs!

If you have never heard of mercury vapor bulbs (MVBs), in short, they can be used to provide both UVB and heat/basking for your bearded dragon using a single bulb for both. Tempting, no?

Generally speaking, we do not recommend this option for beginners since there are too many variables to consider in order to use this bulb correctly. Most members in our bearded dragon community achieve more consistent results by using traditional tube fluorescents made by Arcadia and Reptisun.

Our bearded dragon community experts also warn that using an MVB inside your main habitat can create areas of intense UVB that emanates from the center of these bulbs. As you move away from the middle of the beam, UVB output can quickly drop off and may prove insufficient for your bearded dragon. Using a tube fluorescent disperses UVB output fairly evenly. On the other hand, the narrow beam of an MVB can lead to unpredictable results within your beardie’s habitat that could make it more challenging to create the necessary temperature gradient within your enclosure.

MVBs are also not recommended for smaller enclosures since the effect of the strongest part of the light beam would be magnified in a small space. Just as important, MVBs can cause small terrariums to overheat and become inhospitable or downright dangerous for your bearded dragon.

In the wild, bearded dragons can regulate how much UVB/heat exposure they are receiving by burrowing and hiding. Within the confines of a terrarium, your beardie may have trouble dealing with areas of intense UVB and heat these lamps can produce. Thus, if you do choose to use an MVB, be sure that your bearded dragon has sufficient hiding spaces.

Another bearded dragon community expert has described MVBs as “finicky,” which is unsurprising considering how much your results can vary based on the brand and the wattage of the bulb in question. Moreover, using MVBs safely means carefully following directions to position the bulb at just the proper distance away from your bearded dragon.

To sum up, MVBs are not an ideal choice for beginners and most people who keep bearded dragons as pets. According to UV Guide UK, MVBs are frequently used by professionals who have large terrariums at their disposal of at least 4 to 5 feet across. These terrariums have to be well ventilated to reduce the risk of overheating, and frequently have another independent heating source.

If you feel that you’re up for the challenge of using an MVB for your terrarium, Mega-Ray is considered to be a leading brand.

Another well known brand to consider is Zoo Med.

What Light Does my Bearded Dragon Need At Night?

Your bearded dragon does not need any light at night. Bearded dragons are diurnal, meaning that they are awake during the day and asleep at night.

Red bulbs and moonlight bulbs are frequently marketed for use with bearded dragons but are not appropriate under any circumstances. According to one of our community experts, contrary to popular belief, dragons can in fact see this light, and it will disturb their sleep. Think about it, bearded dragons have an extra cone in their eyes. At the minimum, this means they have better vision than humans and can see things that we cannot. A good rule to go by is, if you can see it, they definitely can see it.

At night, a ceramic heating element (CHE) is your only option. It will produce heat, but no light. To read more more about heating your bearded dragon terrarium, please refer to our Bearded Dragon Heating Guide.
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