Rio Reptiles
Rio Reptiles - A Rescue Resort

  Understanding Lighting & Temps


Two very essential necessities that play an important role in a bearded dragons environment  are lighting and temperatures. It is also not a good idea to get the idea that they are the same.  They may seem to be associated and can be depending on how you setup your dragons enclosure, but have separate functions in how they affect the health of the animal. 

Warning! Do not use any coil (energy saver looking) type fluorescent UV bulbs with bearded dragons.

Dragons need a hot spot, or the basking area which should be the only area in the cage with a high surface temp.  You don't want to heat the whole cage unless it is winter and you're trying to avoid temps below 65ºF.   So you want an ambient air temp between 75ºF and 85ºF. Dragons are naturally attracted to a beam of bright white light and have a little third eye atop their head for sensing where the sun is positioned and where the light comes from.  So a single bright white light is what they are instinctively attracted to, their brains think it's what they need so it is also good for their well being.  This is also how they sense heat and think this is where they need to be to digest their food. I always ask people to test drive their enclosures to make sure the temps are optimum before getting the dragon.  The best way to check the temps is with a temp gun ($20 at Lowes) or a probe type thermometer.  Walmart carries a small indoor/outdoor digital by Accutemp that has a probe on the end of a wire to place under the light and you can put the readout in the cool end.  It also shows humidity which is nice.  Lighting and temps are the most important factors in good husbandry for bearded dragons next to nutrition.  It may seem difficult at first but once you have it figured out it's simple and in no time you'll be a pro.

Proper lighting for a bearded dragon should contain a high amount of ultraviolet light of the proper wave length which is the B or medium wave.  UVB is measured in nanometers and ranges from 320 nm to 280 nm.  All bulbs put out visible light which contains UVA, long wave, but that is not the correct  type of ultraviolet that induces the production of Vitamin D in the skin.  As you should already know, Vitamin D is what allows the body to metabolize Calcium and is more effective in the form which is made by the body from UVB exposure.  There are two type bulbs which are very popular amongst bearded dragon owners and are very highly recommended.

The linear fluorescent tube bulbs come in 18”, 24”, 36” & 48” lengths to accommodate many enclosure sizes.  The pros of these type bulbs is that they are low profile, disperse light across a wide area and are very affordable.  Due to their lower output, the uvlight from these bulbs must reach the dragon at all times and span the entire length of the enclosure for sufficient exposure. The cons of tube bulbs are that their output declines rapidly so that replacement is needed every 6 months and that their output is less intense and D3 supplementation is recommended.  They do not radiate high amounts of heat so a separate bulb for basking is required, however, are much safer to use with smaller enclosures that get too hot quickly. The fluorescents seem to be better for adult dragons that bask less and to help control high temps in warmer regions of the country. The bulb manufacturing companies have had a hard time coming up with a safe fluorescent and the only brand that is accepted is made by Zoo Med called the Repti-Sun 10.  These cost about $20 $25 online and up to $50 in pet stores. Some manufacturers were making fluorescents that had dangerously high outputs of UV and were causing serious eye problems in dragons due to the phosphors, including the Repti Glo 10. Always try to find out the current ratings on bulbs before buying to be sure the manufacturers don't have any recalls.

Mercury vapor bulbs have become very popular and have proven to be an excellent source of quality UV and have a longer use life.  MVB’s are a large flood type design and come wattages of 100, 125, 160 and 275 watts.  When used at the recommended distances, the self ballasted bulbs provide enough heat for basking as well but must be used with adequate ventilation.  The dragon must be basking directly under the light in order to get uv exposure, but since their output is supposedly much higher, shorter exposure times are adequete. Younger dragons seem to benefit more with this type bulb due to their constant basking habits during times of fast growth. Deep domes or high enclosures are needed for these bulbs due to their vertical length, and for safety purposes, a high rated ceramic socket must be used.  Due to specific distance requirements and high heat, they should not be used small enclosures.  If you decide on a mercury vapor bulb, remember that D3 supplementation is not recommended at all and be sure to get current output ratings before buying for the first time or a replacement. Manufacturers of these bulbs have a history of changing materials and specs from time to time which can compromise quality or cause insufficient or unsafe levels of uv. The most popular mvb's are the T Rex Active UV, Mega Ray, Zoo Med'
s Powersun, Exo Terra's Solar Glo. New to the market are Fluker's Sun Spot, Big Apple Herp's Sunforce, T Rex's UV Heat, and the Solar Brite. I have recently purchased a Solartech 6.2 UV meter and will soon be testing the output of all these bulbs at recommended distances and scheduled time intervals to determine use life.

The fluorescent coil bulbs were not mentioned because they have been found to either be insufficient for use with dragons or harmful to their eyes due to the improper phosphors.  Unfortunately many pet store employees have no formal education about many of the products that are sold and are only in the business to make money.  In my opinion they should be removed from the market but maybe some are okay for different species. A good way to tell if you have the correct type bulb is by looking at the price tag, if it was less than $25.00, it's probably not the right bulb or just a uva basking bulb.

Optimum temperatures for a bearded dragon is essential to their bodies digestion process.  It also helps circulation and immune system function, and is needed to support all biological functions.  Young dragons need to support their rapid growth by eating frequently and digesting almost constantly.  This is why babies and  juvies are almost always found basking.  Due to their smaller size and inability to retain as much heat, they prefer higher temps that range from 100ºF to 110ºF.  This can also dehydrate them faster so it is good practice to bathe them regularly or drip water on their nose to lick off daily.  As they grow older the need for a high protein diet goes away and with less frequency of meals, the need to bask isn’t as important.  Adult dragons seem to like their temps in the 90ºF to 100ºF range with the ability get out of the heat and cool down where it is 75ºF to 85ºF.  Many adults will only bask in the morning and after eating while spending the rest of their time lounging somewhere between the temp ranges. 

Knowing what the temps are in your dragons enclosure will help you avoid problems in the long run.  Never guess at your dragons temps! Make sure you use a digital thermometer with a probe so you can accurately tell what the temps are and where.  A temp gun is your best investment and can be found at your local Lowes for $20.  If a dragon doesn’t get hot enough for long enough, undigested food can cause them to throw up or rot inside them.  Even if their normal temps are a little on the cool side for long periods, it may cause them to stop eating, sleep a lot or even brumate.  When temps are too hot or if a dragon can’t cool down when needed, they can become dehydrated and unable to thermo regulate.  Dehydration can cause the build up of toxins, stop digestion and cause the onset of more serious problems such as impaction.

This is only the tip of the iceberg, but having a basic understanding will get you on the right track.


Setting Up the Lighting

There are two ways to setup your bearded dragons lighting. Both ways are good but you'll have to determine which way is best for you and which products you will need.

Fluorescent UVB with Separate Basking Bulb - With this setup you will need to find a fluorescent fixture to use inside your enclosure or on top of your tank. If you are using the typical 40 gallon critter or breeder sized tank, you can go with a 36" hood fixture with a 24" bulb or you can get a simple household type under cabinet style fixture from Wal mart or Home Depot with the lens removed. Be sure it will fit the correct sized bulb. If you have a hand built enclosure, you can get a hard wire style fixture and mount it inside. If a switch is desired, it can be wired in or if you decide otherwise, it can be plugged directly into the wall or into a power strip. Fluorescent UVB bulbs, or the Repti sun 10 to be specific will not put out enough heat to promote digestion in your bearded dragon so a separate basking bulb for heat is required. This can be a special type bulb like the Zoo Med Basking Spot Lamp or you could even use a household bulb, either way. The spot lamps are good because they direct the light and heat in a concentrated area below it without dispersing heat over a wide area. A household bulb can be put in a small reflector dome to help direct the energy towards the basking area similar to the spot bulbs function. If you want to hardwire a fixture of a basking only bulb into an enclosure, either a simple keyless porcelain socket can be used or you can do better by getting the outdoor spotlight fixtures that swivel with a screw in base. These are nice because they come in several colors and will allow you to position the light more precisely for optimum performance.

Mercury Vapor UVB & Heat Bulb - If you have decided on using one of the mercury vapor type bulbs, you have to accomodate the large size due to its 6" long length and almost 4" diameter. It will protrude through the bottom of a normal dome so a deep dome is necessary if it is going to go on top of a tank. If a standard dome is used, the bulb face will protrude through the bottom. Most of these bulbs are self ballasted and put out a lot of heat so safety can be an issue. If you are using a mvb inside a hand built enclosure, the outdoor spotlight fixtures are ideal but must be hard wired in. You just have to remember most of these bulbs cannot be operated at an angle and must face straight downward.

It is also important to remember that if a light is placed on a screen, that screen will filter out a significant amount of valuable UVB rays. It is recommended to remove any screens and replace with a wire type hardware cloth if possible to allow the right amount of UVB to get through.

If you decide to go with either setup, each will provide proper uvb and heat for a bearded dragon. If you ask my opinion, I like using mercury vapor setups with younger dragons because they like the heat and are constantly basking. For adult dragons I like the fluorescent setups because they spend less time basking and more time lounging in cooler temps and will still get the right amount of uvb light.


buy supplies



© 2009-2010 Rio Reptiles. All Rights Reserved