Bearded Dragon Lighting Boot Camp
by Jack Roussy

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Hello everyone, in this document I will try my best to explain the lighting requirements for Bearded Dragon care. I will try to keep it in layman's terms so everyone can understand.

Any drawn images done by me may be crude since I'm no artist but they will help you understand things better.

The "why's" for the lighting

Here are why we all need to use proper lighting for our beloved Dragons.

Basking Light:

The basking light is needed mainly for the heat it generates, a Bearded Dragon needs heat from above for the digestion of it's food, they are cold blooded creatures thus generate no body heat of their own, so without a basking light with properly adjusted temperatures on top of the basking spot, the Dragon wouldn't be able to digest it's food and fall ill over time.

UVB light:

UVB is also very important for a Bearded Dragon. The proper range of the UVB spectrum will help the Dragon self create (along with supplements) vitamin D3 which is needed to help prevent MBD (Metabolic Bone Disease). This disease is debilitating,  a dragon's bones can turn weak and rubbery and cripple a Dragon. So even though humans cannot visibly see UVB light (Dragons can), it is very important to have this and for it to be strong enough.

The Variables:

There are so many variables involved in planning your lighting needs for both Basking and UVB lights. Distance is the biggest problem closely followed by obstructions. The lighting requirements for a 12 inch tall enclosure are way different than that for a 24 inch tall enclosure, a 4 foot wide tank will have different requirements than a 3 foot wide tank and so on. Screen tops are evil for lighting, they can block a lot of the heat from Basking lights from getting into the tank and also shorten the life of these bulbs due to them over heating because of poor ventilation. The best thing I always recommend for the basking bulb is to cut a hole in the screen just a little smaller than the diameter of the dome fixture.

Screen tops are also evil for UVB, screen will block 32 to 38 percent of UVB from getting into the enclosure where it's needed most. That's like taking 32 to 38 percent the cost of your UVB light and tossing it out the window.

Another variable to consider for UVB lights is the age, from testing some of these lights, the UVB strength degrades with time of use. Depending on the style and quality of the UVB light, it needs to be changed out at certain intervals, even though it is still throwing off visible light, the UVB levels may not be enough for a Bearded Dragon which requires a lot of UVB.

Basking lights:

There are 3 kinds of basking light you can use for the generation of heat for your Bearded Dragon...

They are:

Reptile Brand Basking Lights (expensive)

Incandescent Flood Lights

Halogen Flood Lights

The two kinds of flood lights you want to avoid, any light based on either L.E.D. Or CFL (florescent) technology, these put out very little to no heat making them useless for use as a basking light.

When choosing a Incandescent or Halogen flood light, reading the packaging for the light can be very useful, here's what to look for.....

Wattage, for incandescent flood light the wattage is what you see is what you get, not so for Halogen flood light, most will have two wattage numbers, "Actual watts" and "Equivalent to watts". You want to choose by the "Actual watts" on the package since this is what generates the heat you need for your dragon.

The next thing to look out for is the R, BR, or PAR number on the package, these refer to the reflector built into the flood light, best thing to do is keeping this number to 30 (and even 38 for higher watt bulbs). The higher the R, BR, or PAR number, the bigger the radius of light the bulb will put out but with less heat since the wattage of the bulb is being spread to a larger area. A PAR-30 halogen at 50 watts will give off good heat with a large enough radius to keep your dragon's body in the heat so he can digest. This is something you have to experiment with depending on your tank setup and size to get the basking spot surface temps just right.
Please check out Justin Huynh's Tank Tip 10 for additional information.


Depending on the style and kind of enclosure you are using, there are a couple of different kind of fixtures that can be used.

On top of the tank: A good quality dome fixture should be used, one of a decent size (to handle the larger high wattage bulbs) and with the proper wattage handling capabilities (150 watts or more, bare minimum 100 watts). Buying a good quality fixture is a good investment, it will last a long time and with the higher wattage rating, less chance of having problems.

In the tank: (wooden enclosure): A ceramic or a porcelain light socket will work well in these, again, depending on the height of your enclosure. Plastic light sockets should NOT be used as they may not handle the heat from the basking bulb very well and could be a fire hazard.

Screen Tops:

As mentioned above, screen is the best way to rob your basking light of the heat it could be generating inside the enclosure, screen will absorb a lot of the heat that should be going into the tank robbing the basking spot surface by a few degrees of heat. Also, the heat from the screen will rise up into the dome fixture causing the dome to not ventilate properly and shorten the life of the basking light by it over heating. Best thing, make a hole in the screen just a little smaller than the diameter of the dome fixture.


The farther away the top of the basking spot is from the surface of the basking bulb, the higher the wattage you will need to maintain a warm enough temperature on top of the basking spot, there are a few things you can do to adjust this, if the top of the basking spot is too cool, raising the basking spot or lowering the basking light will work, if the top of the basking spot is too hot, lowering the basking spot or raising the basking bulb should work. It's always better to have a bulb that's too hot than too cool, in this case, you can always use a light dimmer to turn down the bulb thus the heat until the desired basking spot surface temperature is reached.

Basking Temperatures:

The best way to measure the basking spot's surface temperature is to use a Temp Gun, these are meant to measure surfaces and give instant readings, just point and click. An alternative is to use a Digital thermometer, by placing it or it's probe on top of the basking spot and letting it sit for at least 10 minutes (for it to adjust to the temp), then take your temp readings.

Basking spot temps should be 100 to 110 degrees, sometimes as high as 115 for baby dragons. If you notice your dragon doesn't want to stay on the basking spot very long after eating, the basking spot may be too warm, some dragon's like it cooler, so this is a matter of experimentation, you can turn down the heat by a couple degrees at a time and see if the dragon start basking. Some dragons like it as low as 90 degrees for basking.

Dial or analog thermometers should not be used in a enclosure, especially the cheap reptile brand kind, they are inaccurate at best.

Night Time Heat:

So many people (due to poor recommendations from uninformed pet stores) believe you must have a RED light on at night. This is so wrong on so many levels. A Bearded Dragon is like us humans, they like it dark to sleep. As for heat, if your house stays above 60 degrees, then you don't need any heat either, a Bearded Dragon likes it cooler at night to sleep, the cooler temps allow for their metabolism to slow down so they can have a good night's sleep.

If your house gets below 60 degrees, you can use a CHE (Ceramic Heat Emitter) to warm up the tank a bit, a CHE puts out heat but NO light, it screws in like a light bulb and come in various wattages for different sized tanks.

UVB lighting:

There are many different kind of UVB lights from many different manufacturers, I will try and explain best I can how to setup your enclosure for proper UVB for your Bearded Dragon.

Here are the different styles of UVB lights......

Coil: These are weak and at one time were bad for your dragon's eyes, but I believe they fixed that part with the newer coils (personally I wouldn't take a chance), these are weak UVB wise and should NOT be used for a Bearded Dragon. Some manufacturers call these "Compact Bulbs", this is wrong, they are Coil Bulbs.

Mini Compact: Please save your money, these are so weak that they are not useful for a Bearded Dragon.

Compact: These are also weak, but can be used in a very small tank (10 to 20 gallon), they have to be within 6 inches of your dragon for it to get adequate UVB from a full size Compact bulb. Also, if you really have to use one of these, make sure it's a 10.0 not a 5.0

Long Tubes: These look like the florescent tubes you see in homes and offices, but they are specialized tubes that put out UVB (household tubes put out NO UVB).

There are different kinds of UVB tubes in different strengths from different manufacturers. I'll get to that later.

MVB (Mercury Vapor Bulb):

I wrote a article on the pros and cons of MVB's, it can be seen HERE.

Metal Halide:

This is fairly new to reptile UVB lighting, These are like a MVB which offer light, heat and UVB but WAY more powerful. I've done a bit of reading on these lights and they are VERY powerful, so much so, I wouldn't recommend these to the average Bearded Dragon owner, they are better suited for very tall enclosures and zoo applications, they are quite expensive and can more than likely fry your dragon if you don't know what your doing with these.

UVB In Your Enclosure.....

In this part of the document, I'll skip the coils and compact bulb and to straight into explaining UVB long tubes.

Their strength come in many various ways, some manufacturers will even resort in calling their products with misleading names or putting the picture of a Bearded Dragon on the packaging of a UVB light that is not strong enough for a Bearded Dragon. Manufacturers that mislead people by calling their UVB tubes with things like "Desert 50", or 25, 50 and so on should be avoided, if they want to mislead you, don't give them your business. The 25 and 50 they are referring to is a 2.5 (very weak, more like a plant grow tube) and 5.0, these are UVB tubes meant for Tropical reptiles, a Bearded Dragon is a Desert Reptile. The number you want is a 10.0. One manufacturer names their tubes with percentages, this is fine, like 10% = 10.0 and 12%.

The next thing in the strength department is the diameter of the tube itself, they are T8 and T5HO, the HO stands for High Output. Both these different sized tubes are acceptable depending on the individual enclosure it will be used with, both need to be 10.0 tubes an not 5.0. A T8 10.0 tube should be mounted inside the enclosure, 8 to 10 inches away from the Dragon (12 inches Max), inexpensive under cabinet fixtures can be had for 18 and 24 inch T8 tubes at Walmart and Amazon, making a DIY reflector (see here) can double the UVB.

A T5HO 10.0 tube is more powerful and is the only tube than can be used on a screen top as long as you have a good quality HOOD fixture and you keep the distance between the tube and the dragon at 6 to 12 inches. The screen top reduces UVB by 32 to 38 percent. A T5HO can also be used in taller enclosures (24 inch tall), when in the enclosure, something that looks like a under cabinet fixture can be used, something like a SunBlaster T5HO fixture with reflector  (when choosing a fixture, make sure it is HO capable, not all T5 fixtures are HO capable). Now with the T5HO being inside the enclosure, you can get away with a longer distance between tube and dragon..... 9 to 18 inches.

The quality of the tube is also important since a good quality tube will put out more UVB and last longer than a cheap UVB tube, my recommendations for both T8 and T5HO tubes are Zoo Med Reptisun 10.0 tubes followed by Arcadia 12% tubes. As far as I'm concerned, the rest isn't worth getting.

The tube length should be 75% the length of your enclosure, so for a 36 inch long tank, a T8 24 inch or a T5HO 22 inch tube would be good.

A while back, I had written a article on the 3 things that can affect UVB, it can be seen HERE, this will give you a good idea as to how UVB works and how it can be affected.


A reflector is important to have with either a T8 or T5HO tube, it can double.... yes, double the UVB, it's like getting free UVB. It does this by redirecting the wasted UVB going up and sideways to a downward direction. I also have a article for how to make a reflector from ordinary aluminum cooking foil, it can be found HERE.

Lights in YOUR enclosure.....

How you place your lights in the enclosure is actually very important, in a smaller tank (40 gallon breeder) having your basking spot with basking light right above the basking spot to one side will keep your basking temps on the basking spot which will also generate enough heat for the warm side of the tank (ambient (air) temps) and will allow your tank to also have a cool side (75 to 85 degrees), in a small tank, placing the basking light in the middle is not recommended since it would mess up having a warm side and cool side of ambient temps. In a larger tank (4 foot long or bigger) then you can play around a little with the basking spot but it's still a good idea to keep the basking spot to the one side and if need be, maybe setup a 2nd basking spot with basking light to keep the cool side at the appropriate temps.

In both circumstances having a UVB tube ahead or behind the basking light so the basking spots gets both heat and UVB is a great idea. See imagine for a rough idea.

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