Juvenile bearded dragons (up to 12 inches) can be kept in a 20 gallon long tank, dimensions 30″ x 13″ x 13″.
Adult bearded dragons should be kept in a 40 gallon breeder tank, dimensions 36″ x 18″ x 18″. This is the bare minimum, and extra floor space as well as climbing room is always appreciated. In fact, lately there has been a shift in the bearded dragon community to suggest that 75 gallons (48″ x 18″ x 21″) is the ideal minimum size for an adult bearded dragon.
Bearded dragons are desert reptiles, which means they need warmth, dry air, and do not need to be misted. That said, they still need a mesh lid placed over the enclosure to keep the lizards in and other things (other pets, falling objects, etc) out. Mesh lids are also handy for supporting heat lamps.
If you build your own enclosure: You can build it however large and in whatever shape you want! Just make sure that each dragon has at least 5-6 sq. ft. of floor space. If you need to figure out your enclosure’s approximate gallon capacity, here’s a handy calculator: http://www.firsttankguide.net/calculator.php.
A great resource for building is http://www.timelessspirit.com/enclosure.html. They mention everything you need to build a healthy, safe terrarium. If you’re looking for more ideas, I have a Pinterest board you’ll find handy.
Bearded dragons are diurnal, which means that they are active during the day. In other words:
- They must have UVB radiation
- Plenty of bright, white light is needed for energy, appetite, and mental health.
The Zoo Med ReptiSun 10.0 High Output UVB and Arcadia Desert 14% are fluorescent bulbs that don’t produce heat, but provide plenty of good quality UVB for bearded dragons across the length of the terrarium. (and the Arcadia is especially good). An 18″-24″ bulb set in an under-cabinet light fixture (with the plastic bulb cover removed) installed inside the tank and over the basking spot works great.
PRO TIP: UVB radiation is completely or partially blocked by glass, plastic, and wire mesh. Therefore fluorescent UVBs should be installed inside the enclosure to be effective.
Some keepers choose to solve both of the abovementioned needs at once with a Mega-Ray mercury vapor bulb. Mercury vapor bulbs produce extra-strong UVB wavelengths necessary for bearded dragons to build and maintain strong bones. They also produce a lot of heat, so you don’t need an additional heat lamp. Mercury vapor bulbs can’t be housed inside standard dome heat lamps because they get really hot — instead, they should be installed inside a wire cage heat lamp with a ceramic socket.
However, it should be noted that mercury vapor-type bulbs only provide concentrated UVB directly underneath them, neglecting the rest of the terrarium. So these may be better used in conjunction with a fluorescent UVB than on their own.
The ideal lighting arrangement for bearded dragons is to create a UVB gradient: Use a mercury vapor bulb for the basking spot, then install a fluorescent UVB spanning about half of the enclosure’s length next to it.
Whether you choose to go for a mercury vapor , fluorescent-type UVB — or both — the bulbs must be replaced every 6 months to be effective.
UVB IS NOT OPTIONAL FOR BEARDED DRAGONS!
Like all reptiles, bearded dragons need heat to digest and maintain their immune systems. Without it, they get sick and die. Since bearded dragons are basking lizards, they use heat most effectively from an overhead heat source that mimicks the sun, like a mercury-vapor bulb.
Juvenile bearded dragons need a basking spot of 105-110 degrees, while adults require 100-105 degrees. Keep the cool end between 80-85 degrees. The wattage it will take to accomplish this varies according to room temperature and distance between the lamp and the basking spot, but a 75w halogen floodlight bulb inside a heat lamp with a ceramic socket is a good place to start.
How do you make sure you’re doing it right? Many recommend placing thermometers on both the hot and cool ends of the terrarium. But that’s not always the most accurate—especially when you have a large, multi-level terrarium. So I recommend using a temperature gun. I got an Etekcity Lasergrip 774 off Amazon, and it’s spectacular. Measures bathwater temperature, terrarium temps, dragon temps, the whole enchilada. Get. One.