Chameleon Cage Set-up: Replicating the Sun

Introduction to Implementing Lighting

Lighting our chameleon cages is an involved execution as we break sunlight up into three different lamps: light for vision, heat, and UVB. Not only do we need to co-ordinate strengths of these light sources, but we need to place them in a limited physical area above our cage where they jockey for space with mist heads, foggers, fans, and whatever else we need to create an appropriate environment. In this module we will review implementing the three functions of replicating the sun.

  1. Daylight
  2. Heat
  3. UVB

The most involved will be UVB.

As mentioned, the common challenge will be not only determining the right strength and shape bulb, but in finding a place to set them for full benefit. Some fixtures come with legs to stand on, some with chain to be suspended, and some with clamps.  Once you read this section, you will have an idea of which lights you will get and can then decide on how you will mount them the required distance from the cage top.

In my examples here I will be placing the cage on a wire baker’s rack with adjustable shelves giving me the freedom to place a “lighting shelf” at whichever distance above the cage I select.

Implementing Daylight

To give the chameleons the bright white light they need for vision we want to provide the best full spectrum lighting we can. Presently, 6500K fluorescent tubes have shown to be effective. We are coming from an era of chameleon’s cages being so poorly lit that they looked like caves in our living rooms. I have not had issues with how close I have T5 or T8 white light bulbs to the top of the cage. Both resting them on the top and suspending above the cage has been effective. The latest LED bars that have come out are quite powerful and I appreciate that strength when I am using my rack system to hold the lights a number of inches above the cage top.

You must consider how much space you have above your cage. When I am using my wire rack, I will have a quad T5 bulb fixture with four 6500K white light bulbs, a single bulb fixture for UVB, and a 10” reflector for my basking bulb. But with set-ups that have reduced space, the UVB and daylight can be combined into one dual bulb fixture. Or else you can used one LED bar and one single bulb reflector.

Implementing Heat

measuring heat for chameleon basking bulb

Our heat bulbs produce a gradient where the temperatures immediately off the bulb are too high while the perfect temperature is somewhere in the cone below. The higher the wattage the wider the area that will be at the desired temperature. Your job is to ensure that the bulb is lifted off the cage top far enough that the chameleon is not exposed to dangerous levels of heat. Chameleons are prone to burning themselves under heat lamps that are too hot. While we give temperature numbers for the basking area in the care sheets, the best way to ensure that the temperature is warm, but not too hot, is to use the back of your hand to check that it is safe. It obviously is a subjective test and you will have to make allowances for your personal sensitivity. But your skin can easily detect temperature and if it is comfortable for the back of your hand to stay at chameleon head level for one minute then it is likely that this is a safe level. You can always use a temperature gun for actual numbers.

When we place the basking bulb we want to be extra careful to secure the light fixture as slipping or falling could be a fire danger. Many of the reflectors, including the one I use, come with clamps that can be used to elevate the reflector above the cage. The danger with using the clamp is that it is easy for it to slip or even fall off once it gets older. If you do want to use the clamp lamp then use zip ties to cinch the clamps tight so they cannot slip.

The best way to accomplish a large area of the cone at a desired temperature without the top of the cage being too hot is to have a high wattage bulb placed a distance away.

Implementing UVB: Know our goals. Know the tools

Our goal for including a UVB light is to provide our chameleon the option of basking in enough UVB that their body can produce the necessary Vitamin D3. On the other hand, we are aware that too much UVB can cause health problems (sunburns, eye issues, and decreased fecundity). Thus we want to make sure that the range of UVB in our cage is both effective and safe. Our execution of this requires us to decide on the Minimum Effective UVI as well as the Maximum Safe UVI.

Minimum Effective UVI: The minimum UVI that must be present in the cage for the chameleon to make the required amount of vitamin D3.

Maximum Cage UVI: The highest UVI that we want the chameleon to have access to in order to avoid UVB “overdose”.

These numbers are exceedingly difficult to nail down with certainty as needs will change by species and lifestage. But all we need is a magnitude. We are including in the cage ample space to hide and get UVI 0 so our main focus is on determining the Minimum Effective UVI. But we are cognizant of the Maximum Cage UVI because, as we will find out when we take UVI readings, the levels coming off of our lamps in the first inches are beyond what is seen on Earth naturally. This is no place for an exposed belly of a chameleon walking upside down on the cage top!

My personal goal is for us as a community is that we are so proficient with our UVB implementation that we do not need dietary vitamin D3. You will note, though, that the advised supplementation routine here does include one or two doses of a supplementation that includes vitamin D3. The benefit of this is that it is generally accepted that vitamin D3 and vitamin A have a relationship with each other and it appears to be a good policy to give them together. Thus the supplementation of preformed vitamin A will be done with vitamin D3 for now. So, this is not to try to make up for a failing UVB lamp. It is unknown how much help a twice monthly dose of D3 would give in a cage where the UVB has failed.

The Minimum Effective UVI

There is much on going work to determine what the minimum effective UVI is for different species of chameleons. The greatest amount of work, so far, has been done by Dr. Gary Ferguson with panther chameleons. The Ferguson zones were named after him and they list the Veiled, Panther, and Jackson’s Chameleons in Ferguson Zone 3 which is UVI 1-2.6 with a maximum of UVI 7.4. (If you are interested in the discussion about Ferguson Zones, a thorough paper by Dr. Francis Baines discusses UVB in the captive environment.

The Jackson’s Chameleon was listed as Zones 2-3, though feedback from the hobbyist community suggests that the Jackson’s Chameleon belongs in zone 3. Testing will continue, but I would lean towards zone 3 rather than 2. Once again, all these numbers are there for us to use as a step for further testing. They are not meant to be definitive. It is our responsibility to take the hard work done by these scientists and expand and add to the collective knowledge. Remember, they have all reptiles, amphibians, and other animals they work with. We live and breath chameleons. It is OUR responsibility to continue their work and add to what we know about chameleons. Expanding on their work is NOT saying they are wrong. It is being actively involved in the work instead of passively consuming. The more people experimenting the better.

The Ferguson Zones were derived from interpreting the natural data and provide a reasonable starting point for us to take it to the next level. We in the chameleon community need our UVB to provide enough energy that a female can lay a fully calcified clutch of eggs. This is the final confirmation check we use to refine these numbers. It is absolutely true that babies, adults, and gravid females may need different amounts of UVB, but with a proper cage set-up the chameleon will have the option to UVB bask and hide as much as they need.

The calcified egg test was performed for Veiled Chameleons by Pete Hawkins and myself where we confirmed that UVI 3 was sufficient to provide for a calcified clutch. This does not mean that UVI 3 is the Minimum Effective UVI, but it is an effective UVI and we will use UVI 3 as the target UVI in our set ups because of this confirmation.

Jonathan Hill, of iPardalis, shared with me that he has raised up three generations of panther chameleons under UVI 3. He used a variety of bulb/fixture/distance configurations, but tuned them in with a Solarmeter 6.5 to UVI 3 at the basking branches. The results are stunning. This is significant because his only supplementation was using the Arcadia EarthPro-A which has no vitamin D3 (or preformed vitamin A, for that matter). This is an implementation of the multi-generational test well over with four generations of eggs produced where the mothers and their mothers have never had synthetic vitamin D3. Their vitamin D3 came solely from UVB at UVI 3. So this establishes UVI 3 as a valid effective level for panther chameleons. Of course, this does not mean UVI 3 is the Minimum Effective UVI. But we know that UVI 3 is in the Effective Range for both Veileds and Panthers by the passing of the calcified egg test.

I am confident that we have further refinement of this number in the near future as more and more members of the chameleon community test these UVB levels and supplement with vitamin D3 free powders.

3rd gen Panther Chameleon from Jonathan Hill

This is a third generation male Panther Chameleon that has been raised under UVI 3 and supplemented with only Arcadia EarthPro-A. The significance of this is that there has been no synthetic Vitamin D3 or Vitamin A in this multi-generational colony maintained by Jonathan Hill, of iPardalis.

4th gen Panther Chameleon eggs from Jonathan Hill

Fourth generation well calcified panther chameleon eggs produced by three generations of panthers raised under UVI 3 and no supplemental vitamin D3 or vitamin A beyond standard gutload practices. This is from a multi-generational colony maintained by Jonathan Hill, of iPardalis.

The Maximum Cage UVI

In nature, chameleons get one UVB level at a time. They do not get twice the UVB just by crawling up a couple of inches. Our lights, on the other hand have a distinct gradient and we must be smart about it if we are to provide the right levels over the right area without allowing our chameleon to wander into dangerous UVB levels. Since UVB damage is not only in intensity, but also in duration of exposure this is a difficult parameter to determine. Presently, the one controlled study I am aware of is a personal study I performed to compare the effects of Veiled Chameleons raised under UVI 3 and UVI 6. I saw no increased growth with UVI 6 so I determined there was no benefit to giving more than 3. Although this was not meant to determine if 6 was a health level for long term usage I can at least put a stake down and suggest that there appeared to be no issues at UVI 6.  Though, as the commonly respected Ferguson Zones lists UVI 7.4 as the maximum for zone 3 you’ll find I have shifted my Maximum Cage Level on my graphics from 6 to 7.4. This is to make it simpler for people learning to make connections. Panther Chameleons are at a lower elevation so the argument could be made for erring on the lower side for them. Yellow Crested and Machakos Hills Jackson’s Chameleons show similar basking behavior (out in morning and retreat in afternoon) and come from about the same elevation as Veileds so the numbers would, presumably, be able to be used for a start point. The higher in elevation a chameleon lives the more UVB it is exposed to simply because the higher the altitude the less atmosphere filtering happens.

Learning to Effectively Use the UVB Gradient

Gradients are inherent in the UVB lamps we use and we must use them wisely.

Every UVB lamp has a cone-like shape of UVB emitting from it. This cone can be broken up into the following sections for ease of understanding and execution:

Caution Zone: Readings directly off the UVB bulb will be unearthly. For perspective, UVI 13-15 is around the maximum we are recording in the standard chameleon habitat at high noon. The highest UV Index measured on Earth is UVI 43 on Bolivia’s Licancabur volcano. Within an inch or two of these artificial UVB lamps you can easily see UVI 40 or even up past 150 where one has to wonder how accurate the meter is! And these are measured through the filter of one layer of screen. To be sure, the UVI level drops dramatically each inch you move away, but, especially with babies that crawl the top panel, we need to be very aware of the levels directly off our lamps. If we do not elevate the lamps then we allow our chameleons to expose themselves to ultra-high levels of radiation. We do not know exactly where the dangerous UVI starts, but I believe I am reasonable in assigning anything beyond what a chameleon could possibly encounter on Earth into the caution zone. We do not know where the dangerous intensities start and there, assuredly, is not a simple value.  The Ferguson zone 3 places this value at UVI 7.4 so it is a good target value until experimentation gives us a more accurate number.  This becomes a major husbandry consideration as placing T5 bulbs, the most popular form, directly on the screen top will introduce levels way beyond this into your cage. Remember that these lamps were designed to produce enough UVB that it can reach a basking lizard on the floor of the cage. When we set up a system for arboreals where the lizard can crawl up to an inch or two of the bulb we must adjust our implementation. This is a prime example of how important it is to understand the tools we work with. Thus, any value over UVI is consider in the Caution Zone and is best kept above the cage.

Working Zone: This is the most important zone to turn our attention to and to experiment with. This will include the values of UVB we want inside the cage. This working zone could be thought of including two sections. The basking branch splits the Working Zone into the basking level UVB and the UVB replicating the filtering of light into the foliage. With the information we presently have, the basking branch should be placed so that the back of the chameleon would be in UVI 3. So, made simple, the basking branch is around UVI 3 (or just below a couple inches to account for the height of the chameleon) and the top of the cage is at UVI 6. Below the basking branch the UV Index will dissipate. We have not shown where the minimum effective UVI is for chameleons so, until more tests are run, we will accept the lower limit of UVI 1 suggested by the Ferguson zones.

Selecting a UVB Profile

To select the proper UVB solution consider the shape you would like the UVB to take in your cage. By learning the principles here you are able to make an intelligent decision as to which UVB lamp to use. But, by far, the most useful and used form of UVB is the T5 High Output fluorescent bulb. They are available from 2% UVB strength to 14% UVB strength (the percentage of light output in the desired UVB wavelengths). And we further modify the strength by the fixture and the distance above the cage. You can select a UVB lamp with the following steps. Note that if you are confused with all these options and just want to put together your cage there are build guides provided that require no deep understanding of the secrets of the universe! So if you don’t absorb everything here do not worry. You can always build an effective cage set-up with the build guides and come back to soak in the fine details.

  • Find the lamps that cover the cage area you wish to have UVB. With the vertically orientated “pillar” shape cages this is generally the width of the cage. So a 24” wide cage would use a 24” wide fixture. You do have an option with the wide format cages to irradiate just the open area. If you recall, the Forest Edge concept applied to a wide format cage has one half of the cage open and one half is dense leaf cover. UVB is needed only in the open area to simulate the chameleon being able to hide in the dense foliage. So, with a 45” wide Dragon Strand Large Atrium a valid design option would be to use only a 36” UVB fixture or even a 24” fixture. Chameleons have been shown to recognize and specifically bask in UVB even when it is separated from heat so you do have the option to make a UVB area in your cage.
  • Review the different configurations of the lamp size that will give you the UVB gradient that provides a UVB Working Zone which covers both the height and length of your chameleon.

Giving UVB recommendations is a tricky thing. The same bulb can give very different results depending on the fixture it is in, the nature of the reflector, and the age of the bulb. Therefore, the graph shown here will be for specific lamps. The Arcadia ProT5 line is, by far, the preferred product simply because it is a bulb and fixture packaged together so any numbers I share here are able to be reproduced in your set-up. Any attempt to give UVB advice that does not include fixture and whether it is going through screen will be haphazard at best. Even my previous versions of this page which specified a single bulb fixture or a multi-bulb fixture would have various results depending on which fixtures were chosen.

Test conditions:

The UVI chart that follows has been tested with lamps that were run for at least 100 hours and had been on the day of the testing for at least 30 minutes. All numbers given here, unless specified, were tested through the screen of either a Dragon Strand cage or a ZooMed Reptibreeze cage. Both Dragon Strand and Reptibreeze screen had the same filter effect.

Having your own Solarmeter 6.5 is the best approach!

The absolute best way to set up a UVB system over your chameleon cage is to have a Solarmeter 6.5 UVI meter. That way you can measure your exact lamp strength and create a custom configuration. You will also be able to track the lamp’s slow degradation over the year and adjust when necessary. The problem with making a chart such as the one below is that readings can change dramatically depending on where the meter is sitting or how it is pointing. Each lamp will give a different reading depending on how long it has been on and how long it has been in use. Thus you should expect that these are magnitude numbers only. They are enough to get you started.

IMPORTANT: UVI measurement is highly imprecise. The level read depends on lamp active age, lamp on-time, brand and shape of reflector, position of the meter, and angle of the meter. The most accurate way to tune in your UVB lamp is with your own Solarmeter 6.5 meter. These charts provided can offer a snapshot of a sample of these bulbs.

UVB penetration map

Chart 1: Depth of UVB light from various commercially available UVB bulb and fixtures

Selecting a UVB for a Standard Chameleon Cage

Once you understand UVB you are able to make most UVB sources work. But the simplest approach would be to choose between the Arcadia ProT5 6% UVB or the Arcadia ProT5 12% UVB. This product has the advantage that it is a bulb/fixture combo so the charts  provide have the greatest chance of being accurate. Of course, getting your own Solarmeter 6.5 is the best way to tell. The main decision point is whether the UVB fixture will be on top of the cage or if you have the open to elevate the UVB light above the cage.  When directing how to use UVB lights you must, in every case, dictate how far below the UVB bulb the basking branch or back of chameleon is, and how far above the cage screen top the UVB light is suspended. If you can only rest the UVB on top of the cage then the ProT5 6% is the way to go. If you have the option of suspending the UVB light 6″ above the cage then the ProT5 12% is the way to go. UVB bulbs are chosen by where they are mounted. Since panthers and Veileds both have done very well under UVI 3, the light chosen is not chosen because of species, but because of how close it will be mounted to the basking branch.

UVB over a 2x2x4 cage

The Compact Fluorescent Light (CFL)

Compact Fluorescent Lights (CFLs) were developed to bring fluorescent technology to the wide spread screw-in light sockets. CFLs have gotten a bad rap in the chameleon world because of the under powered bulbs included in the ubiquitous Chameleon Kit. But they are a tool like every other lamp and need to be used properly. Even the low powered 13W bulbs have use in baby cages. But we should not do a broad brush across all CFLs because of the 13W 5.0 in the Chameleon Kit. When you jump up to 26W lamps you are getting respectable penetration. In fact, as the chart below shows, most CFLs will require you to prop them up above the cage to ensure you don’t get unnaturally high levels of UVB in the cage. For example, I placed an Exo-Terra 26W 200 on top the cage any chameleon crawling on the screen under it would be blasted by a UVI in excess of 150. I caution the community to be careful of making over reaching statements regarding CFLs. The Reptisun 13W 5.0 CFL is the baby brother of some pretty intense lamps.

The measurements below were taken with a 10.5″ reflector so the resulting UVB area was quite satisfactory for a standard chameleon. Smaller reflectors will focus the UVB beam a bit more.

CFL UVB map for Chameleon cage

There has been some confusion in the community over whether these CFLs are “T5” or not.

T5 HO lighting is a technology that is encased in a 5/8” diameter tube (T5 = 5/8”, T8 = 8/8”, etc…). This tube can be straight as in our linear bulbs, pig-tailed like Exo-Terra CFLs, or in a triple U bend (up and then down) like ZooMed and Arcadia do with their CFLs. They are all using the same T5 HO technology. So it is correct to identify all of these as T5 HO CFLs. The reason why CFL output is so much lower than when in their linear form is that they spend so much of their length shining into each other instead of in the direction we can use the energy. Any part of that bulb that faces another bulb gets its energy absorbed and lost to us. Only the light that gets to the reflector or faces in the right direction escapes to do our chameleons any good.

Now, anyone comparing the actual bulbs will note that the CFL bulb was of a diameter smaller then 5/8″. So can this still be “T5”? The answer is pretty simple. What we label “T5 HO” is really a set of technologies that make it work (phosphors, glass, etc..). The prime value of the 5/8” diameter aspect of the T5 is to provide a standard dimension that everyone can design around so all linear bulbs and fixtures from different manufacturers will work together. When they design CFLs they can fudge the diameter of the bulb to fit in a tight space because it is mounted in an adapter that interfaces with the A series standard light bulb connection they must fit. They are still using the T5 HO technology even though the “5” is more “5-ish”.

Resting the UVB fixture on the top of the cage

One important thing to note is that, with the modern technology available to us, many of our UVB bulbs can produce UVB levels beyond what a chameleon would encounter in the wild and, in some case, more than would be recorded on Earth. Resting these bulbs directly on the cage top exposes our chameleons to unnatural levels of UVB. While the energy dissipates quickly, we chameleon people must contend with our chameleons walking to top of the cage upside down – especially young chameleons. So these young chameleons are exposing their belly to unnaturally high levels of UVB. It is important that we understand what risks we are incurring by placing the bulbs directly on the cage top. It is pretty much accepted that chameleons can detect UVB and “UVB bask”, but it is not yet known if they are able to regulate it safely. If their ability to regulate heat safely is any indication (they easy burn themselves and continue to bask), we should not assume they have any ability to avoid UVI 42 on their belly. Chameleons seems to know to go find heat or UVB when they need it and they leave the heat and UVB when they have had enough, but they do not seem to have a concept of defending against too much. This would make sense as they have never had to deal with such temperatures or UVB levels in the wild. The health effects of this kind of UVB exposure on a chameleon has yet to be determined, but it would be fool hardy to assume there is no effect until proven otherwise. Thus I recommend suspending the UVB lights above the cage the number of inches necessary to remove the highest UVB levels from the cage interior.

Why is this so complicated?!?!

The reason why it is so important to understand how our implementation of UVB works is that new technologies and new information is constantly becoming available. By understanding the underlying principles we can understand how to change what we are doing to take advantage of advancements. Are Compact Fluorescents Lights or Mercury Vapor bulb effective or not? By understanding the profiles and gradients you can make an intelligent choice as to whether it is appropriate for your situation.


This module is part of a class on Setting Up Your Chameleon’s Cage where you learn how to build up a complete chameleon environment from start to finish. From this point you can either go back to the home room and see the other modules in this class or go on to the next module where we dive into how to set up an effective chameleon hydration strategy!

"Setting Up Your Chameleon's Cage" Home Room

panther chameleon in big cage

Next Module: Chameleon Hydration Strategy

Chameleon Hydration Strategy