Fluorescent Lighting Guide


Feel free to share links to this website but to ensure accuracy and availability of the latest version please do not redistribute the image without permission. All values listed were supplied with permission by Dr. Frances Baines from her detailed lighting test reports. You can find them at UV Meter Owners Yahoo! Group along with other invaluable information about lighting.


Bearded Dragons are Ferguson Zone 3 Baskers. See this page for more information on thermal-gradients.  

Lights should always be positioned overhead and in a way that the animal is not going to spend time staring into the bulb.
Lights should always be positioned out of reach and at a safe distance to enure safety from thermal burns or over exposure to UVB.
Even the best UVB bulbs can still be hazardous if used improperly. 
UVB works best in conjunction with heat, placing the UVB near the basking area will help get the most benifit from it. 

The purpose of the image below is to get a rough idea of the output a new bulb will have at a given distance for setting up UVB lighting in a vivarium. Type, fixture, reflector, screen and much else influences the output of a bulb so these are estimates.  To use the chart... 

1) The upper area explains two methods of lighting.  When possible the sunbeam method is good for bearded dragons as they are Open Sun (zone three) baskers from the bright sunny outback. Wild dragons bask in the morning and evening, at a UV index of up to around 4-5. For our pets it's a good idea to play it safe by sticking to values between 3-5 for the basking area on down to zero thus providing a photogradient in the same manner as heat. (This is the method when Mercury Vapor Bulbs are used)  For smaller setups a Shade method may work better - this simulates a day spent in the shade and is more of an average of exposure (1.0-2.6). Either way - more uv is not always better and it's possible to over expose your pet if the vivarium is not furnished with appropriate shade/hides. UV Index is a good method of comparison since it is reported by weather services around the world. (Historical UV information for Alice Springs Australia. Each month will also have hourly information for given days ) 

2) Pick a chart based on whether you have screen between the bulb and the dragon. The values in Chart B are all estimates based on an average loss of 35%. Not all screens are created equal, learn a bit more here and here (bottom of page).

3) You can either pick a distance away you have to work with, or the bulb+fixture you have to work with - then find the UVI you want to achieve. Bulbs are across the top; they are numbered and the legend is at the bottom for what fixture and configuration was used. Reflectors make a huge difference, and even the shape and type of reflector does as well. Don't expect a homemade aluminum reflector to preform as well as a engineered one, but it is better than nothing. 

Remember this is just an estimate and is intended to show the approximate differences from one configuration to another. Dr. Baines data is accurate to her particular setup and no two setups even with the same equipment will measure the exact same.