Lighting

UVB Lighting

Most enclosures will require two different light sources. One light to provide UVB and one light to provide the temperature required to maintain a basking area. Lighting and temperatures are both equally important and closely tied.

For information on basking lights and maintaining appropriate temperatures see our Heating page.

Why Dragons need UVB

Simply put, exposure to UVB allows the bearded dragons skin cells to manufacture Vitamin D, this in turn is synthesized into vitamin D3. Vitamin D3 plays a major role in governing the use, absorption and metabolizing of calcium in the dragon's body. Without proper UVB lighting dragons will suffer ill health and calcium deficiency. Long-term calcium deficiency will result in metabolic bone disease.

UV rays do not penetrate plastic or glass and should never be mounted over these obstructions. Screen lids, while commonly used, will obstruct usable UVB by up to 40% so positioning them over this obstruction is not recommended.
Dragons spend much of their time basking so it is necessary when using florescent tubes or compact fluorescents that this area is also within the range of UVB. Raised platforms or branches help to utilize the use of UVB by allowing the dragon to be in closer proximity of its effects. With florescent tube UVB, dragons should have the ability to come within a minimum of 6" of the source. (For compacts and mercury vapor bulbs please read manufacturers specifications)
The components of manufactured UVB break down over time and become ineffective even though the bulb may still emit light, so it must be replaced periodically. We continually monitor the effectiveness of our UVB lighting with the use of UV radiometer but in general UVB bulbs should be replaced every eight to twelve months. Natural sunlight cannot be completely reproduced and is undoubtedly the ideal situation for dragons. When outside temperatures are 24 degrees Celsius (75 degrees Fahrenheit) or above, placing your dragon in the sunlight in a screen-covered enclosure is a clear benefit to their health (don't forget to provide a shade source as well to prevent overheating).

Most commonly used UVB styles

Florescent UVB tubes are offered in assorted lengths and properly installed, can offer a wide area of UVB exposure.

Compact Fluorescents* offer a lesser area for optimum UVB exposure but can be useful in many situations. The bulbs are used with a standard clamp lamp.

Mercury Vapor* bulbs have a high (limited area) UVB output but additionally offer a heat source.

* Please pay careful attention to manufactures instructions when using compact fluorescents or mercury vapor bulbs as both have a higher potential for harm if not properly used or installed.

Our personal choice is the full-length florescent UVB and incandescent heat lamp combination. Most of our enclosures also have an additional full-length "daylight" florescent.

Lighting Cycle

Over the dragons "summer", lighting should be on for 14 hours daily and off for 10 hours.
During the dragons "winter" or shutdown period, commonly known as brumation, lighting should be gradually decreased to be on for 8 hours daily and off for 16.

There should be no direct light sources during "night time" hours.

MORE ON UVB

It is not clearly understood exactly how much physical exposure to UVB is required for dragons to synthesize vitamin D3 nor are there any published guidelines as to the optimum level of UVB exposure. There has been some research done with other species of reptiles that suggests they, themselves may self regulate their exposure to UV through positioning and cover and it is speculated that this may also be the case with bearded dragons. There is still much to be learned in regard to this subject and we eagerly await scientific data that can clarify many of the questions that remain.
For a better understanding of UVB in relation to reptiles, results of brand comparisons and some highly informative links, UV Guide UK offers a wealth of information and can be found at UV Guide.