Solar radiation bands for bearded dragons UVB UVA and visible light

Simplifying Bearded Dragon Lighting and Heating setup

The equipment needed for the heating and lighting setup for bearded dragon’s is:

  • Basking or normal light light and lamp fitting if needed
  • UVB bulb and lamp fitting
  • Ceramic heat emitter and fitting
  • Thermostat (day and night)
  • Timer for lighting (may not be needed if the thermostat provides the light timer function as well)
  • Heat lamp guards
  • Thermometers and hygrometer

Outside of the housing itself, this is the most expensive part of the bearded dragon housing setup.

Without proper temperatures, lighting and humidity, reptiles are susceptible to disease (Rossi 2006). Understanding heating, lighting and related equipment will reduce the margin of error.

UV Wavelengths in short

UV is split into three wavelength groups. The shorter the wavelength, the more harmful the UV but also the less it can penetrate the skin. The three types of UV are:

  • UVA – Long wave ultraviolet A. Ranges between 320-400 nm. UVA makes up the vast majority of UV that reaches us and is what causes tanning and aging of skin in humans. UVA influences the way we see our environment, food, etc. The level of UVA impacts how reptiles see their environment and food as well.
  • UVB – Medium wave ultraviolet B. Ranges between 280-320 nm. Often the range is shown as 290-320 nm. The reason for this is although the UVB light wavelengths go down to 280 nm, little of it reaches the earth’s surface until 290 nm. UVB penetrates past the superficial skin layers. Bearded dragons require UVB for vitamin D synthesis and to metabolise calcium.
  • UVC – Short wave ultraviolet C. Ranges between 180-290 nm. Extremely dangerous to life on earth but filtered out by the atmosphere.
Solar radiation bands for bearded dragons UVB UVA and visible light
Bearded dragons make use of all 3 bands of solar radiation being UV (UVA and UVB), visible light and infrared.

Breaking Down the Equipment Required

What lights do you need for a bearded dragon? Bearded dragons need UVB and visible lights (normal light bulbs or basking bulbs).

Visible Light

Visible light lights up the environment, it is the equivalent of daylight in enclosures. This is particularly so at the basking spot which needs to replicate the sun as much as possible. This impacts bearded dragons interaction with their environment much the same as it does for humans.

Visible light is simply that, if we can see it then it is visible light. UVB bulbs will contribute to visible, however it may not be sufficient to light the environment well and could be focused only on the basking area. Low levels of visible light or poorly placed lighting will likely slow activity down and could impact other behaviours such as eating.

Can you use a regular bulb for your bearded dragon? You could use a regular bulb for you bearded dragon. However, the main difference is that we tend to use more of a yellow light whereas bearded dragons are better with a whiter light. Something more natural to that of daylight is best.

A regular bulb purchased for whiter light, could be used for your bearded dragon. However, consider using a bulb with a frosted surface or in some other way diffusing the light. Also look for wide angle light, lights (such as LED strips) that will distribute the visible light over wide area. Visible light is best across a large area rather than focused.

Normal regular household light bulbs may be used for bearded dragons
Normal regular household light bulbs may be used for bearded dragons. Household bulbs typically have a yellow tinge to them. Lights with a white or closer to sunlight glow are better.

Many of the basking bulbs are incandescent and as such add to the heating of the environment. However, they are not the best choice for visible light since they have a narrowly focused band of light. Flood lights may provide a wider area of light.

Do I need a basking bulb for bearded dragon? Visible lights for reptiles are sold as ‘basking’ bulbs. You do not need a basking bulb for bearded dragons housing but you do need sufficient light to make the house bright during the day time.

When selecting lighting, consider the intensity of light. Intense light may be blinding. The art to lighting is to provide a bright white even light in the basking area that does not blind or irritate the eyes when being looked at.

Visible light can be distributed across much of the housing as long as there is ‘shaded’ area. However, it should at the least focus on the basking area.

In summary, yes you could use a regular bulb for your bearded dragon if it were white and diffused light. Some of the led strip lights may also brighten the bearded dragons house without becoming blinding. Basking bulbs are the manufacturers version of adding to visible light and typically produce heat to the environment.

UVB Lighting

Bearded dragons require UVB for vitamin D synthesis and to metabolise calcium, critical to their health. In bearded dragons’ artificial UVB lighting has shown to be more effective than vitamin D3 supplementation at high doses in maintaining 25-hydroxycholecalciferol plasma levels (Mans, 2017). The post by DVM Amna Ahmad on simplifying calcium and vitamin D3 goes into more detail.

Only lights sold specifically for UVB provide UVB. The cost of UVB bulbs is linked to their quality.

Full spectrum lighting does not provide UVB. Bulbs designed to produce UVB will state it on their packaging and will be more expensive than normal light bulbs (aka basking bulbs).

The strength, or effectiveness, of the UVB light diminishes with distance from the bulb. The manufacturer provides instructions as to the ideal distance from the bulb.

Types of UVB bulbs that can be purchased include:

  • Compact fluorescent,
  • Tube fluorescent,
  • Mercury vapor, and
  • Metal halide.

The strength of UVB light also diminishes as the bulb ages. All UVB lights will require replacing according to the manufacturer’s instructions which will generally be between 6 to 12 months. Never buy second hand UVB lights, chances are they will no longer be effective.

Always keep a spare UVB light on hand. The lights can break at the most inconvenient times. It will not be wasted even if the current bulb does not fail since it will serve as a replacement for the existing light which has a limited life.

Inadequate UVB is associated with secondary nutritional hyperparathyroidism and metabolic bone disease (Mans, 2017). See the post by DVM Donald Buchanan on metabolic bone disease and what to do about it for more information.

Do you leave UVB light on at night for bearded dragons? No, you do not leave UVB light on at night for bearded dragons, UVB light is for basking in the day.

UVB bulbs for bearded dragon house setup
Bulbs that emit UVB will be labelled on the packet. UVB bulbs are essential for indoor bearded dragon housing.

Compact (COIL) Fluorescent Lights

Compact fluorescent lights, aka coil fluorescent lights, have been associated with photokeratoconjunctivitis and photodermatitis (Wilkinson 2016). However, the issue has been resolved and incidents have been reduced (Wilkinson 2016).

Regardless, their inadequacies at distributing UVB are clearly highlighted in this video by Frances Baines, M.A., Vet.M.B., M.R.C.V.S. The video also shows the distribution of the the tube fluorescent and the Arcadia D5. VIDEO

Fluorescent Tube Lights

UVB fluorescent tube lights will provide a greater area of coverage. The Arcadia T3 D5 has earned a reputation of being one of the best UVB lights available particularly when coupled with a reflector.

The heat produced by UVB fluorescent lamps is so insignificant that it will not add to the heating of the environment. This means that fluorescent lamps do not need to be connected to heat control on thermostats. However, they should be connected to timers to turn on and off for day and night. Bearded dragons do not need light at night and should be provided a period of darkness.

The fluorescent tube light does not need to (and should not) run the entire length of the enclosure. Bearded dragons are capable of regulating their own UVB exposure in a correctly set up habitat and need to be given options to get out of UVB and heat as needed. Overdoing exposure has its own set of dangers.

Mercury Vapor Bulbs

The Mercury vapor bulbs will produce both light and heat which will contribute to the heating of the environment. This can make them ideal for areas that require a boost to heat and can encourage basking since the heat and UVB are focused directly over the same spot.

Mercury vapor bulbs add to the heat of the environment but cannot be connected to thermostats, even dimming thermostats. Ensure there is a safety margin when using mercury vapor bulbs which includes:

  • Using a big enough enclosure that the bearded dragon can distance itself from hot spots, and
  • That the light is not a high enough wattage that it can cause excessive danger. i.e. use a 100 watt rather than a 160 watt.

Regardless, their inadequacies at distributing UVB are clearly highlighted in this video by Frances Baines, M.A., Vet.M.B., M.R.C.V.S. The video also shows the distribution of the the tube fluorescent and the Arcadia D5.

Metal Halide Lamps

Metal halide lamps require ballasts. Like the mercury vapor bulbs, metal halide lamps produce heat and they cannot be connected to any thermostat, including the dimming thermostats.

Heat Sources for the Bearded Dragon’s House

When bearded dragon’s are warm they react differently as to when it is cool. Once warm you are likely to see them being more active, alert, eating and so on.

As a side note, if your bearded dragons needs taming and you are finding that sometimes it seems all good and other times it is not at all tame, it might be the temperature that is making the difference. If you have been handling your bearded dragon when it is cool, it will not react as much. Once they are warmer, they are far more animated and reactive. Temperature may not be the reason, but it is worth monitoring and assessing.

Ceramic Heat Emitters

Ceramic heat emitters (CHE) are the most common suitable source of heating. The ceramic heat emitters only produce heat, no light. They are bought mostly in black or white with no different between the two outside of colour.

Bearded dragon heat lamp CHE
Ceramic heat emitters suitable for providing heat in bearded dragon housing.

There are different shaped ceramic heat emitters. The various shapes are designed to distribute heat differently.

Using the lowest wattage ceramic heat emitter possible to maintain the desired temperature will mean that it can stay on a little more consistently. Using a high wattage will force the thermostat to keep turning it on and off as the desired temperature is reached quickly.

What wattage heat lamp is required is dependent on the temperature/climate the setup is in. Lighting and heating setups will be far safer and more flexible if setup for multiple lower wattage lights and heat sources, than for higher.

For example, if it is particularly cold, rather than purchase a 150 watt ceramic heat emitter, purchase 2 x 75 watt and distribute the heat. High wattage bulbs get extraordinarily hot and have a narrow range of heat. It is best that the heat and light is distributed over, at the very least, the bearded dragon’s body, but preferably greater area than that. This would give the bearded dragon more choices so it can find the optimal spot for basking in the moment.

CHEs are reasonably cheap therefore keeping a range of wattages and spares is feasible. These bulbs are generally pretty hardy and do not need replacing until they cease to work. By having a small range of different wattage’s available, increasing or decreasing the level of heat throughout the season changes becomes easier and ensures there are spares when one fails.

Heat Mats

Are heat mats ok for bearded dragons? It is never recommended to use heat mats for bearded dragons. However, where it is difficult to maintain heat overhead without going to extremely high wattage ceramic heat emitters, then it may be a useful addition to heating.

If it is difficult to retain heat then it is likely that you are in a cold climate and/or using housing made of glass, perspex or other materials which don’t have sufficient insulating properties.

Heat mats provide heat from both sides. So as to retain as much heat as possible they need to be placed inside the housing or outside with with a 5mm thick polystyrene sheet over the back to prevent heat loss.

The preferred position for the heat mat is on the wall near the basking area. The heat mat can be placed either inside or outside of the house.

Heat mats can be fixed on to walls with adhesive tapes that can take the temperature. Normal sticky tape will not be suitable. Ensure the placement does not allow for any living creature to get in between the heat mat and the enclosure wall, especially for baby bearded dragons.

Heat mats may also be placed under substrate at least a centimeter or 2, or better still, under the enclosure. Neither of these placements of heat mats are ok for bearded dragons as they do not meet the requirements for overhead heating. Nor does a wall placement but it can contribute to the basking area temperature more effectively than under floor heating. Heat mats under substrate may be vulnerable to claws piercing it when digging.

Precautions with heat mats:

  • Heat mats damaged or wet must not be used.
  • When used with glass be cautious that the glass does not overheat which may cause burns or crack the glass.

The above is generalised guidance. It is important to read and follow the manufacturers instructions before setting up the heat mat.

Thermostats

Thermostats are designed to control the temperature. Thermostats do this by reducing, sending packets or turning off electricity in order to maintain the temperature to the minimum and maximum temperatures you program the thermostat to.

Some essential points are that for thermostats and timers are:

  • Bearded dragons do not need the lights on at night, and
  • There is a minimum and maximum temperature needed in the bearded dragons house.

Thermostat (and timers) help to:

  • Supports natural behaviours by being able to program consistency to day/night and summer/winter cycles.
  • Safer for the bearded dragon, temperatures won’t go to low or too high which impacts health/immune system.
  • Make it easier on you since you won’t have to turn on and off the lights manually. Plus it is impossible to manually manage the heat to a consistent temperature.
  • Save electricity. If you are paying for electricity then thermostats will return their cost.

The key points when selecting a thermostat are:

  • Dimming or pulse
  • Day and night feature
  • Wattage capacity

Some extend to providing timers for lighting. Lighting should be connected to the thermostat control as it will turn on and off as the thermostat adjusts temperature.

Not all thermostats have a day and night setting, some will only offer one setting. These are ineffective at providing a day and night cycle and not suitable for an optimal setup. Buy a good thermostat up front. It may cost you an extra 50, or perhaps less. Worth it for the long-term comfort of your reptile and your own peace of mind.

The three main thermostats are:

  • On/Off thermostats (heating only)
  • Dimming thermostats (heating and lights)
  • Pulse proportional thermostats (heating only)
thermostats in bearded dragon light setup controls heating and lighting
Thermostats provide essential relief to control temperatures and maintain consistent cycles.

If you were to choose between on/off, dimming or pulse thermostats, the dimming or pulse will be best. If lights need to be added to the thermostat, use dimming thermostat.

When buying a thermostat, if you cannot find on the packaging what type of thermostat it is, chances are that it is an on/off thermostat. Dimming and pulse thermostats offer superior functionality and the manufacturers will want potential customers to be aware of that fact.

When selecting a thermostat ensure it has sufficient wattage for the devices it will carry. For example, a thermostat with a 600 watt capacity is good, some are much less than that. Just calculate the wattage of the devices you will connect to determine the minimum wattage you need. For example, two 100 watt ceramic heat emitters is 200 watts.

On/Off thermostats simply turn anything attached to them on or off to maintain the required temperature. The power is always either completely on, or it is off.

On/off thermostats are not suitable for lights but will do fine with ceramic heat emitters, heat mats and heat wires. They do not usually carry a high load and so may be limited to under 300 watts.

The temperature is not precisely controlled at all with variations of degrees as the thermostat can be slow to kick in or to turn off.

On/off thermostats are the cheapest in the range of thermostats and don’t do well in keeping precise and uniform temperatures.

Dimming thermostats maintain an electric current but reduce the amount of electricity going to the connected devices. This is the same as a light dimmer in a house, where you can turn the dimmer down and it will reduce the brightness of your house light.

Dimming thermostats require a minimum load of 40 watts.

Basking lights that add to the heat of the environment can be added to a dimming thermostat with the exception of mercury vapour and metal halide lamps.

The thermostat will increase or decrease the amount of power going to the device as need to control the heat. It does not turn on and off. Because of this, you would not be able to put devices on it such as a house radiator which require full power but it will run ceramic heat emitters, heat pads and the like that does not require the full voltage.

Dimming thermostats provide more control over precise and uniform temperatures compared to on/off thermostats.

Pulse proportional thermostats pulses packets of electricity to the connected devices. To adjust the temperature, the pulse proportional thermostat will increase or decrease the time between pulses. This keeps a much more consistent temperature than an on/off thermostat.

Pulse proportional thermostats are good for heating elements such as ceramic heat emitters, heat mats and heat wires.

Do you need a thermostat for a heat mat? Yes, you will need a thermostat for a heat mat or any source of heat. Thermostats control the temperature of the environment. The temperature controls on heat mats are not controlling the temperature of the environment, only a single element and will not provide any precise control over the entire environment.

Thermostats are not thermometer’s and its readings cannot be used as such.

Timers

Light timers will control the time the lights turn on in the morning and off at night. Bearded dragon’s do not need light at night. Light timers are exactly the same ones you would purchase for any other lighting in your home.

Simply attach the lights your bearded dragon needs (visible light and UVB) and set the timer. The mechanical ones are easy to set and visualise what it is set to without having to press any more buttons like the digital timers.

Some thermostats have light timers separately wired to that of the thermostat. If this is the case, then a separate timer is not needed.

Lamp fittings

The key points when selecting light and heat fittings are:

  • Reflectors help intensify and/or focus light
  • Buy a fitting with a higher wattage capacity than you will need
  • Buy ceramic fittings
  • Whether it is designed to sit inside or outside of the enclosure
  • If designed to fit inside the enclosure, can a heat guard be fitted on to it

The UVB bulb, UBA bulb and ceramic heat emitter will each need a fitting. Use ceramic fittings rated above the wattage bulb you intend to use in the fitting.

This gives you flexibility later in changing to higher wattage bulbs if needed, especially if you are unsure in the beginning as to what wattage you will need. Plus, it gives a little peace of mind that they are made to take more heat than you intend to subject them to, extra safety margin.

For example, purchase the fitting with the highest wattage rating that you are likely to use, i.e. a 150 watt fitting. You can now use any wattage bulb up to 150 watts. Having 2 smaller wattage bulbs such as 2 x 75 watt bulbs is going to distribute heat better, reduce extreme hot spots and with that should never reach the extremities of temperature it is designed for.

keep a safety margin when selecting heat emitters for bearded dragon lamp fixtures
Purchasing a lamp fitting that can take a higher wattage than you intend to use provides flexibility later if higher wattage is needed and gives a little extra safety margin.

Purchase a brand you are comfortable with over what price it is. Although the initial purchase price might be more, it is a once off purchase as long as the fitting is reasonable, and it is used appropriately. Faulty or poorly designed fittings can cause fires.

Removable fittings (ready to plug in) made specifically for reptile habitats, typically have benefits such as reflector shields and are easy to move around. Regardless of which type, buy porcelain fittings that will cope with the heat the bulbs will generate.
Fittings that will be installed in the bearded dragons house should be encased in a heat guard.

Heat guards

The key points when selecting heat guards are:

  • Installation
  • Ease of access to changing bulbs

Bearded dragons, like many reptiles, get burnt. Preventing direct access to the hot fittings can be done by:

  • Placing accessories in a manner that does not provide easy access and gives a range of heights to bask at, plus
  • Mesh heat guards.

Mesh guards can be fitted to help prevent direct contact but can themselves be used as a climbing object. Buy guards that give easy access to changing bulbs as needed.

You will not need heat guards if the hot fittings are outside, on top of the bearded dragons house.

hot lamp guards in bearded dragon housing
Covers over hot lamps prevent direct access to the heat source.

Thermometers and Hygrometers

Thermometers are required to monitor the environments heat. Using different types provides an easy means to validate their accuracy and provides redundancy. Types of thermometers include thermometer guns, digital thermometers, digital thermometers with probes and analogue.

Two thermometers, one an analogue and the other a digital thermometer with a probe, will give a good range. Thermometer guns are great gadgets, but nothing beats having thermometers already set in place which you can immediately visualise the temperature of the environment while walking past.

Thermometers with probes are easy to place. Only the probe needs to be positioned in the required location and the display can be placed where it is easy for you to view.

What not to buy

Bearded dragon’s do not require light at night. Bearded dragons do not need red, orange, blue or black lights at night. The only light required is during the day and the day lights should be white, closer to that of natural sunlight.

bearded dragon does not need red light
Bearded dragons do not need red light at night or in the day.

Hot rocks or heated rocks are renown for having hot spots and resulting in burns. They are not required and certainly not needed in a well setup environment.

Heat rocks are renown for causing burns. Bearded dragons are good at sensing heat from overhead, not from underneath. There are many reptiles that end up with burns from heat rocks and poorly set up or unguarded heating.

Reptiles are prone to burn injuries with one of the culprits being heated rocks. While there are some who sell these products claiming that this is no longer an issue with the latest heated rocks and that they are safe there are still vets who are having to treat the resulting burns reptiles. The heat rock does not need to malfunction to cause burns, it can simply have hot spots and mixed with the sensory deficiency of the bearded dragon’s belly.

Bringing All the Equipment Together

Our goal as reptile keepers is to bring the heating and lighting together to imitate days, nights and seasons. We do this by:

  • attaching the lights bearded dragons need (visible light and UVB) to either a timer or thermostat, and
  • attaching heating devices to a thermostat,
  • focusing the heating and lighting to replicate the natural environment and sun,
  • using the thermostat and timers to control the lights and heating to a specified duration, and
  • monitoring with thermometers and hygrometers.

If we do it right, then we provide opportunities for bearded dragons to interact with their environment in a way that encourages natural behaviours. In addition, it increases comfort and reduces potential health issues that are otherwise caused by poor setups.

Bearded dragons naturally bask using the sun overhead as its primary source of heat, and certainly light. In captivity, we provide a basking spot where heat and UVB is focused at the least the entire length of the bearded dragons body.

The UVB light that a bearded dragon needs will spread over at least the length of its body when basking. The UVB light should not be over the entire length of the enclosure and the housing needs to be big enough that when they need to get out of the UVB, they can. Bearded dragons can regulate their own UVB requirements. Forcing overexposure by not providing areas of respite has its own set of hazards.

Keep the heat and UVB sources together, just as it would be if it were the sun. Poorly setup and spread out lighting and heating could cause confusion which can result in abnormal behaviour (i.e. hiding, lack of appetite, sluggish behaviour) and/or development of illness where the environment is inadequate.

Heating and lighting set up for bearded dragon indoor house
The examples of heating and lighting setup focus the heat and light in the basking area. Lights (bulbs for visible light) can be spread further to lighten a wider area in the environment. However, the basking area needs to be well lit, replicating the sun beating down on the basking spot. A peaceful, not so well lit spot should be provided for retreat.

Manufacturer’s will have instructions on how far away the UVB light should be from the bearded dragon. In addition to that, there should be a minimum distance of 12 inches from the beared dragon to the heating and lighting to avoid burns (Boyer, 2015).

Heating is primarily provided by the ceramic heat emitters which are connected to the thermostat. The heat may be propped up by basking bulbs (normal light bulbs) and UVB bulbs depending on the type used. Only some UVB bulbs emit sufficient heat to add to the temperature of the environment.

For example, an incandescent light bulb and UVB mercury vapor bulb will add to the heat of the environment. If the heat is still inadequate and the ceramic heat emitters are at the highest level you consider safe, then a heat mat may be attached to the wall (not floor) of the bearded dragons house.

Normal lights (visible light) and UVB lights are controlled by a timer, turning them on and off at set schedules for morning and night. They should not be connected to the thermostat. Thermostats will either turn on and off the lights as it adjusts the heat or it may dim them, neither is a great option but the first will shorten the bulbs life quickly.

There should be no plastic, glass or other obstructions between the UVB light and the bearded dragon, with the exception of mesh heat guards.

Screen mesh may be between the bearded dragon and its heat and light sources. The tighter the mesh, the more UVB is blocked out. Tanks will typically have quite a tight metal mesh screen, just another reason that glass tanks do not make for ideal enclosures.

Heating is required both during the day and at night. During the day sufficient levels of heat may be gained if a Mercury Vapor UVB and basking light are used together.

A ceramic heat emitter (CHE) on a thermostat is ideal for use during the day and night. Placed on a thermostat the CHE can be maintain the environment at a reasonably consistent temperature. The thermostat will cut the CHE out once the right level of heat has been attained and turn it back on when the temperature cools from the desired range.

Do bearded dragons need light at night? Bearded dragon’s do not require light at night. Bearded dragons do well with darkness for sleep, as do humans. Heating may be required at night depending on the temperature. However, the thermostat will adjust the temperature as needed.

What wattage does a bearded dragon need? The wattage a bearded dragon needs is dependent on a few factors including:

  • the temperature of the room it is housed in
  • how big the bearded dragons house is, and
  • the type of housing provided.

For winter, in Australia temperate climate zones (which is mostly southern areas of Australia), for houses that do not have heating or cooling and where your bearded dragon is brumating, you may need 100-150 watt of ceramic heat emitters. For summer you may need as little as 40 to 75 watt. In cooler parts of the world, you may not need much different if your home is heated or cooled.

Once you need more than 100 watt, or close to, it is best to separate into multiple bulbs or ceramic heat emitters. Rather than 1 x 150 watt ceramic heat emitter, have 2 x 75 watt which gives a more even temperature in the bearded dragons house and a better basking experience by reducing hot spots.

Do bearded dragons need heat at night? Whether bearded dragon’s need heat at night is dependent on what the temperature of the environment is. Refer to the temperature requirements of bearded dragon’s in the table on this post.

In some locations, night-time heat may be sufficient, such as in the majority of Australian locations during the middle of summer. However, that may not be the case if the houses were unusually cool (such as with air conditioning. Whether its winter or summer, cool or warm the temperatures will be adjusted by the thermostats.

If the climate is warm, then providing the bearded dragon outside housing during that time will be ideal. The inside housing equipment can be turned off and the bearded dragon can be offered appropriate outdoor housing to take full advantage of the sun and shade as needed.

Temperatures and Photoperiod

With the setting up and adjustment of temperatures and photoperiod throughout the bearded dragons house and life we aim to:

  • Replicate a minimum of 2 seasons (summer and winter),
  • Replicate day and night over the seasons,
  • Provide a basking area that encourages optimal conditions for basking,
  • Provide an area of shade to cool down and get a deep rest.

For simplicity of care and avoidance of potential issues, we tend to provide only 2 seasons in captivity being Summer (includes Spring and Autumn) and Winter (brumation time).

Within these 2 seasons, we control the duration of the photoperiod (light) and the heat to replicate the 2 seasons plus day and night.
There are two terms used in the heat set up referred to as ambient and gradient.

Ambient temperature refers to more of a consistent temperature across the entire environment. Ambient temperatures are provided during times that the bearded dragons do not bask, mainly night-time and for winter (brumation). For bearded dragons this does not need to be exact uniform temperature across the entire enclosure, more a generalisation.

The thermal gradient refers to a temperature range that starts from a cool zone and graduates into the hottest zone, which is the basking area. Thermal gradient is provided during the day, not night-time. The thermal gradient allows the bearded dragon to choose between heat and cool as it needs. The bearded dragon housing needs to be big enough that a thermal gradient can be provided.’

The preferred optimum temperature range (POTR) which is required for the optimal functioning is between 35°C to 39°C (95°F to 102°F) (Doneley, 2006). To enable the bearded dragon to achieve these temperatures, we provide slightly hotter basking area and a cool area to shuttle between heat and cool as needed.

The photoperiod refers to the period of time light is provided regardless of whether it comes from normal light bulbs, UVB or a combination. However, the expectation is that the UVB light will be on for the bulk of the photoperiod.

How long do you leave the lights on for a bearded dragon? How long you leave the lights on for a bearded dragon is varied by the time of year. In summer, the lights are left on for around 12 to 14 hours (Boyer 2015; Doneley, 2006; Baines, 2017) except during hibernation. This is, give or take an few hours depending on the month, pretty much what we expect our Australian daylight duration to be.

Optimal body temperature is required for optimal metabolic process functioning including digestion, growth and the immune system. Bearded dragons preferred body temperature is 34°C (Cadena & Tattersall, 2009).

The basking temperature needs to be at an optimal range that encourage sufficient basking time without overexposing. If the temperature in the basking area is to low, it will give the bearded dragon little choice but to remain under the UVB longer than it needs to just to get warm. If it is too hot, then it may not bask long enough to get sufficient UVB.

Overheating the basking area will reduce the time spent basking. Overheating the housing with nowhere for the bearded dragon to escape to, will cause death. Temperatures over the early 40°C enter the dangerous zone. If a bearded dragon’s internal temperature rises to 46°C (114°F) it will result in death (Baine 2017). Heat kills bearded dragons far quicker than cold. Bearded dragon’s heat up faster than they cool down (Bartholomew and Tucker as cited in Schäuble and Grigg, 1998).

Bearded dragons will shuttle between basking and cooling as they need. Provide branches and objects that enable the bearded dragon to choose its preferred position for the moment. It can do that far better than we can.

What temperature should my bearded dragons house be? The temperature of your bearded dragons house basking zone should be 35-40°C (95-105°F) for proper skeletal development (Strimple and Strimple, 1998). However, there are also variations of temperatures for day and night, winter and summer.

Is heating required at night? Depends on the temperature. Some areas will be fine without night heating. Using a thermostat will help prevent the need to be concerned if heat is needed or not as it will maintain the temperature to the programmed settings.

Temperatures between 15-21°C (60-70°F) are insufficient for reptiles to effectively digest and their immune system is weak (Divers and Mader, 2005). On the other hand, these temperatures are insufficient for normal brumation (Divers and Mader, 2005).

Rather than avoid providing a more natural cycle with lower temperatures, ensure that before setting the winter cycle, that the annual vet check has been completed to get the all clear on health and parasite loads that could cause much damage. Not providing brumation temperatures and photoperiod is potentially linked with overweight reptiles and reproductive diseases such as ovarian tumours. See the post on fat bearded dragon’s.

Is 10 degrees too cold for a bearded dragon? In captivity, 10°C (50°F) is cold for a bearded dragon in its active (summer) cycle. In the wild, temperatures over days of 10°C (50°F) is cold enough to trigger brumation (Doneley, 2006).

As a generalisation for reptiles, Divers and Mader (2005) recommend temperatures do not drop below 21°C (70°F) for reptiles during their active cycle (summer cycle) at night.

For the onset of winter, the duration of light in the day reduces, and this is replicated by leaving the lights on for your bearded dragon for around 8-12 hours (Boyer 2015, Doneley, 2006). Bearded dragons house temperature is dropped with the basking area reduced to 80°F and night temperatures 60-75°F (Boyer 2015). Once the bearded dragon enters brumation, the lighting can be switched off.

The reduction in lighting and heating in winter provides a more natural environment and may induce brumation (link to the post on brumation and care during the winter sleep). Interestingly, brumation has also been linked to helping keep bearded dragons a little trimmer around the ol fat pads (post in fat bearded dragons).

Bearded dragons may already be off their food or slowing down by the onset of winter. Once they have entered brumation, the basking area can be switched off and an ambient temperature can be provided.

Do not reduce the temperatures to the low 60°F range for winter if, your bearded dragon is not an adult, it is ill or has a load of parasites. Low temperatures are dangerous to sick or parasite loaded reptiles.

Ensure the bearded dragon does not have a belly full of food. Digestion is ineffective in low temperatures and will become rotten rather than digested.

The table below shows the recommended times and temperatures for how long you leave the lights on for your bearded dragon and heating during the day, at night-time and brumation (winter).

Summer basking zone12-14 hour photoperiod (Boyer 2015; Doneley, 2006; Baines, 2017)
35-40°C (95-104°F) (Strimple and Strimple, 1998)
38-40°C (100-104)°F (Baines, 2017)
40°C (104°F) (Doneley, 2006)
Summer cool zone25-28°C (77-82°F) (Baines, 2017)
21°C / 70°F (Boyer 2015)
Summer night-time
Ambient temperature
15-20°C (59-680°F) (Jepson, 2011)
18-21°C (65-70°F) for adults (Baines, 2017)
24-27°C (75-80°F) for hatchlings (Baines, 2017)
Do not go below 21°C (70°F) for reptiles in general in summer cycle (Divers and Mader 2005).
Winter (brumation)
Ambient temperature
8-12 hours photoperiod (Boyer 2015, Doneley, 2006)
15-23°C / 60-75°F (Boyer 2015) for brumation only

How to set up bearded dragon lighting and heating

Different light and heat sources require slightly different placements to produce the best possible outcome. In all setups a thermostat should be used to maintain consistent temperature and improve comfort of the enclosure occupant.

Using CHE and Mercury Vapor UVB

Where a ceramic heat emitter (CHE) is used with a mercury vapor UVB bulb (UVB with additional heat source) and a basking bulb (visible light with additional heat source), the placement is simple; all the elements are placed as close together as possible.

The CHE should be placed on a thermostat to maintain consistency in temperature and avoid overheating. Do not place lights on a thermostat, their continual turning on and off as the thermostat maintains the temperature will significantly shorten the life of the bulbs and likely cause disruption to the reptile’s environment.

The CHE can be placed in between the two light sources or placed closest to the centre. If placed central it will assist in providing the ambient temperatures required for night-time.

CHE and Fluorescent Tube UVB

For the ceramic heat emitter (CHE) and fluorescent UVB combination place the CHE and the basking light to one side of the UVB light. This setup provides maximum heat and lighting in a concentrated area with sufficient white light provided to encourage activity.

The fluorescent lighting should not be the length of the enclosure. Bearded dragons are capable of discerning when they have had sufficient UVB and remove themselves from it given the right conditions (i.e. temperature gradient) in the enclosure.

Setting Up Bearded Dragon Lighting and Heating Mistakes

In these two setups, the heat and light is spread across the tanks. In the first image the UVB tube lighting is spread across the entire enclosure leaving the bearded dragon with only a burrow in the heated basking zone to seek respite. The thermal gradient was almost non existent with the spread of heat between the two lamps almost crossing over both halves of the glass tank.

enclosure set up mistakes

In the second tank the thermal gradient was non existent with the ceramic heat emitter on one end, the UVB mercury vapor on the other and the basking light in the middle. This resulted in behavioral issues, particularly lack of appetite and health issues. The correction was as simple as placing the fittings together.

Bearded dragon heating setup mistakes

In the wild

In the wild, bearded dragons do not spend all day in the sun basking in direct sunlight. In the peak of the heat on a hot summers day they will be out in the morning, seek cover in the middle of the day and become active again in the afternoon.

They may go up a tree to get more sunlight, or to access warmth in the winter. They may also use a tree to get shelter from the sun.

Providing a microhabitat requires the heating, lighting and accessories to be placed in such a way, that it encourages natural behaviours. To do this, we need to understand what the natural environment is like and how it is used. Studies show that the Pogona barbata doesn’t come down from the trees much during autumn, unlike in summer (Schäuble and Grigg, 1998).

In South Australia, once temperatures drop to around 10°C (50°F) for a few days, bearded dragons will seek a spot to commence brumation in (Doneley, 2006). In spring, once the temperatures rise above 12°C (54°F) the bearded dragons will come out of brumation (Doneley, 2006).

Real UVB for Bearded Dragons

Sun induced vitamin D3 synthesis cannot be matched by artificial UVB lights. Real sunshine is the best thing you can provide your bearded dragon, even if it is only for a few half hour stints in a week.

25-hydroxycholecalciferol is the major form of circulating vitamin D3. Experiments with tortoises show that even after 35 days of exposure to mercury vapour UVB bulbs or fluorescent UVB lights they had lower levels of 25-hydroxycholecalciferol plasma than when they started (Mans, 207). Those outdoors had normal levels (Mans, 207).

UVB cannot penetrate glass, plastic or solid objects. A bearded dragon basking at a window is not receiving UVB, simply heat and light. If a window is the only means to provide UVB then open it and allow what light can come through whatever screens are on the window.

Since for most the outdoors offers a lot more freedom in terms of space, large enclosures can be provided outdoors. Adding climbing accessories, rocks and hiding areas will make for a more stimulating environment and protection when feeling threatened. After all it only takes a bird to fly over to feel threatened.

There is more information about UVB and vitamin D3 in the post on ….

For calculating the cost of electricty for keeping bearded dragon’s with heating and lighting, see the post on pet bearded dragon’s costs and licensing.

Bearded dragons locating themselves at different basking levels in direct warm sunlight.

Troubleshooting

If you cannot provide an effective temperature gradient, then the bearded dragon’s house is too small.

Are the thermometers placed correctly?

  1. Baines, F. 2017. Your First Bearded Dragon Care Information. January
  2. Boyer H. T., DVM, DABVP. 2015 Diseases of Bearded Dragons. AV017 Conference Note. (Reptile & Amphibian Practice) Pet Hospital of Penasquitos, San Diego, CA, USA.
  3. Cadena, V., and Tattersall, G. J. (2009). The Effect of Thermal Quality on the Thermoregulatory Behavior of the Bearded Dragon Pogona vitticeps: Influences of Methodological Assessment. Physiological and Biochemical Zoology, 82, 203-217
  4. Divers, S. J. 1996. Basic reptile husbandry, history taking and clinical examination. In practice. February 1996 DOI: 10.1136/inpract.18.2.51
  5. Doneley, B (BVSc, FACVSc). 2006. Caring for the Bearded Dragon. Proceedings of the North American Veterinary Conference. Small Animal Edition. Vol 20 Orlando, Florida. p 1607-1611.
  6. Jepson, L. 2011. Bearded Dragons. Pet Expert
  7. Mans, C. Dr. med, vet., DACZM. 2017. Reptiles: Managing Husbandry Related Disorders. University of Wisconsin, School of Veterinary Medicine
  8. Rossi, J. V. 2006. General husbandry and management. In: Mader DR, editor. Reptile medicine and surgery. St Louis: Saunders. p. 25–41.
  9. Schäuble, C., and Grigg, G. 1998. Oecologia (1998) 114 (4). pp 461-470 https://doi.org/10.1007/s004420050470
  10. Strimple, P., and Strimple, J. 1998. Bearded dragons: a beginner’s guide to captive husbandry and reproduction. Reptiles USA Mag, Annual: 28–44
  11. Wilkinson, S. L. Reptile Wellness Management. Veterinary Clinics of North America: Exotic Animal Practice Vol 18, Issue 2, May 2015, Pages 281-304
bearded-dragon-in-sunshine
Bearded dragons locating themselves at different basking levels in direct warm sunlight.

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