Naturally, lighting belongs naturally to the species-appropriate terrarium. The lighting is secured by different lamps. In the last decades a lot has happened in this area, so that the imitation of nature-like lighting conditions becomes increasingly easier. This article is intended to give a rough overview of the different possibilities of illuminating a chameleon terrarium.
Basic information on lighting
Before putting together a lighting setup, you have to consider what goals you want to achieve with the lamps you use. Chameleon terrariums are mainly about creating sufficient brightness to make the animal feel comfortable and to imitate the natural habitat as well as possible. A second, just as important purpose is the warming up of the chameleon, as its metabolism can otherwise not function properly, as in all ectothermic animals. And a third, equally important point is the supply of vital UV-B radiation in order to produce vitamin D. In addition, the light should suffice for the plants in the terrarium to grow. It would also be good if the light used comes close to the colour vision of the chameleon, because – unlike us humans – it also sees in the UV-A range. Therefore, for example, the colour temperature (Kelvin) and the colour rendering value (Ra) are completely unsuitable for assessing the suitability of a lamp for chameleon terrariums. They are based on human vision. But what we as humans feel as bright and beautiful, doesn’t have to be the same for a chameleon.
Metal halide lamps
These lamps are known in terraristics under the abbreviation HQI (Osram calls them so). They require a ballast and function as gas discharge lamps in which metal atoms are excited by electrons and emit energy in the form of light. HQIs are inexpensive to operate and achieve a high brightness of up to 100,000 lux, which is even similar to nature (a sunny day has about the same lux number). They are therefore well suited for the basic illumination of chameleon terrariums.
For more than ten years there have been HQIs, which also emit UV-B and thus of course become even more interesting, as they cover all areas required for a chameleon: Brightness, heat and UV-B radiation. These lamps include the Bright Sun from Lucky Reptile, the Solar Raptor from Econlux and the MD lamps from Reptiles Expert, all of them often used by chameleon keepers. Which UV index for which chameleon species Madagascar should be available at most (!) can be read from the daily profiles of the different regions in the chameleon and habitat data section.
Of course, there is no lamp that would not also have disadvantages. In metal vapour lamps with a UV-B component, the radiation is often so strongly concentrated that it can cause burns in the central beam of the lamp. Lamps are better when the radiation is less concentrated, but rather distributed more evenly (usually as a “flood” variant in the trade). For domestic use: If the lamp is held over a white sheet of paper, the light cone should be evenly distributed and not have an extremely bright spot in the middle.
UV metal halide lamps must always be suspended at a safe distance or measured exactly with the solar meter 6.5 (see also notes for mixed light lamps). In addition, they have a shorter service life than conventional HQIs (the latter often lasted for years). Also important: HQIs must always cool down for a good ten minutes after they have been switched off. During this time they cannot re-ignite, so they will not start even if power is restored. Likewise, HQIs need a few minutes to “burn up”, i.e. to unfold their full function.
Mercury vapour lamps
Mercury vapour lamps (called HQL at Osram) are high-pressure discharge lamps in which a gas discharge with light development occurs when a voltage is applied. Mercury vapour lamps always require a ballast. HQL used to be used a lot in the keeping of chameleons, but were increasingly replaced by the development of UV metal vapour lamps and mixed light lamps. They emit relatively little visible light, but provide a good UV-A component in the light in the terrarium.
Mixed light lamps
Mixed light lamps (Osram HWL) are, as the name suggests, a mixture of two lamps: the incandescent lamp and the high-pressure mercury vapour lamp. They emit bright light, UV-A and heat at the same time. Disadvantages of mixed light lamps are the relatively high power consumption in comparison to the emitted light, the uneven spectrum and a constant flickering. The latter is very likely well visible to chameleons with their highly developed eyes. If you are looking for a lamp to burn all day long over the terrarium, metal halide lamps and fluorescent tubes are more efficient than mixed light lamps.
In the case of UV mixed light lamps, which are increasingly available on the market, there is still the problem that even within a single batch there are strong fluctuations in UV-B radiation. While some lamps do not emit UV-B at all right from the start, others emit sufficient UV-B, and others emit far too much. If you want to ensure sufficient UV-B radiation from your chameleon, you cannot avoid purchasing a 6.5 Solarmeter and measuring the lamps monthly. Often you can use lamps much longer with the measurements and save money, or, conversely, return unsuitable lamps with too little UV-B directly or take them out of use before the chameleon suffers a deficiency. This page provides a more detailed overview of the various UV mixed light lamps on the market.
Special mixed light lamps: Osram Vitalux
Osram has been producing a very special mixed light lamp for decades, whose glass is transparent to UV and can therefore be used to supply UV-B to chameleons: The Osram Ultra-Vitalux 300W. It does not require a ballast and has a very long service life. For us, it can be used for more than five years without any significant reduction in the UV index (we even had some for 10 years). The lamp has been on the market since 1928 with small improvements, has more than proved itself during this time and originally comes from human needs. It was used in the prophylaxis and therapy of rachitic children. With chameleons, Vitalux only needs to be used for 30 minutes a day, always keeping a safety distance of 80 to 100 cm from the chameleon. As with many other light sources, a porcelain socket is suitable for use, as the lamp becomes very hot during use.
If you cannot regularly measure your UV mixed light lamp or metal vapour lamp with a Solarmeter 6.5, you should not go without this form of saving your chameleon’s UV-B supply. By the way, the Radium Sanolux is identical in construction to the Osram Ultra-Vitalux.
Together with metal halide lamps, fluorescent lamps are among the most efficient ways of illuminating terrariums. They illuminate the chameleon terrarium flat and evenly, but cannot concentrate the light with a reflector. They are therefore not suitable for a sun spot, but for the basic illumination of a terrarium. The light does not reach particularly deeply into the depth, so that fluorescent tubes are particularly suitable as basic lighting for not particularly high terrariums.
The most common fluorescent lamps used in chameleon keeping are T5 and T8 tubes. They require a ballast and differ in diameter, service life and some technical details. The luminous efficacy of a T8 tube with ECG is similar to a T5 tube with ECG. However, the T5HE (HE stands for high efficiency) available today are much more efficient, so switching from T8 to the newer T5HE can reduce your electricity costs.
Compact lamps are fluorescent lamps; they are “wound up” fluorescent tubes. Due to this changed shape, the light is more focused and reaches higher irradiances in the UV-B range than the same models in tube form. However, the light emitted and also the UV-A radiation are minimal, so that compact lamps emit a very unnatural light overall. Sun-like light would combine strong brightness with UV-A and UV-B radiation.
Unfortunately, there have been cases since 2007 in which compact lamps from various manufacturers emit too little UV-B radiation, causing eye diseases in chameleons and other reptiles. Since the problem is still not completely solved despite revised lamps, we advise against the use of compact lamps for chameleons at present in principle.
In incandescent lamps, light is produced by incinerating a metal wire and then emitting light and heat. They mainly produce heat and only little light, but no UV radiation that can be used for the chameleon. They can therefore be used as an additive for chameleon terrariums if metal vapour lamps or mixed light lamps do not reach the desired heat at the sunny spot. Halogen spots are mostly used for this purpose. In particularly damp terrariums, halogen spotlights can also be used outdoors.
Light emitting diodes (LED)
The trend in living rooms has been towards LED for years, a light-emitting semiconductor device. LED have the great advantage that they produce visible light for people with extremely low energy consumption and without heat generation. Here, however, the disadvantage for chameleons also comes directly to bear: LEDs do not cover the visual spectrum of reptiles. They always have a strong turquoise effect on reptiles. What we humans perceive as bright and great unfortunately arrives quite differently with chameleons because of the other vision. Attempts to assemble individual LEDs as close together as possible to form a “mixed light” unfortunately do not resemble the light spectrum of the sun and it remains questionable whether the light distribution is even at all or whether “coloured shadows” are created everywhere for the chameleon. Chameleons additionally need heat sources, as they are ectothermic. LED could therefore only be used in combination with other lamps.
Overall, the cost-benefit ratio for light in chameleon terrariums is currently much better served by metal vapour lamps.
Attaching the lamps
With chameleons, it is extremely important to install all lamps outside the terrarium. Most holders build a light box, i.e. a frame above the terrarium, which is open towards the top and to which the lamps are attached. Chameleons are climbing artists and at some point they reach the most impossible places. Protective bulb cages, as offered for other reptiles in the pet trade, are unfortunately unsuitable for chameleons. In most cases they can still reach the lamps – not least with their shooting tongues – or at least get close enough and burn themselves sensitively. Unfortunately, burns are still one of the most common diseases in chameleons kept in terrariums.
The terrarium for a chameleon should always have a gauze lid so that sufficient light can penetrate. Perforated sheeting or similar takes too much light and is not suitable for chameleon terrariums.
In Madagascar there is no extreme change of day length over the year. On the island there are around 11 hours of sunshine and 13 hours of darkness throughout the year, with deviations of a maximum of two hours during the course of the year. In Europe, on the other hand, the daylight varies enormously over the year with over 16 hours of brightness in summer and less than eight hours of daylight in winter (depending on the country). There are now two ways to deal with this discrepancy.
Either one ignores the seasonal differences and stubbornly drives the 11-13 light scheme to imitate Malagasy conditions. This means, however, that the lamps above the terrarium already switch off in summer when it is still light outside. In all rooms with windows, chameleons notice that it is still light and usually remain active until dusk. On the other hand, the light still runs over the terrarium in winter, while it is already pitch-black outside. It can happen that the chameleon has already gone to sleeping position long ago, although the terrarium light still shines.
The more common variant for many keepers is to adjust the day lengths of the chameleons held in Europe to the outside hours of sunshine, i.e. to leave the light on longer in summer and to shorten it in winter. With this light regime, many chameleons become more inactive, paler and eat less in winter. As soon as the days get longer again, they return to their usual activity and colour.
Imitation of sunrise and sunset
If you hold your chameleons in windowless or relatively dark rooms, you can slowly switch the lamps on and off one after the other to simulate the sunrise and sunset. In rooms with windows, the animals usually depend on the ambient light anyway. It has often proved successful to switch on fluorescent tubes first and then gradually switch on the heat and UV-B lamps. Fluorescent tubes can also be dimmed to make the transition as sunlike as possible. A dusk of up to 50 minutes, as we are used to in Germany and central Europe, does not exist in Madagascar, by the way. The sun disappears within about 15 minutes, and reappears just as quickly in the morning.
Night and Moon Lights
In the zoo trade and in the Internet, so-called “moon lights” are offered in many places, which one switches on at night over the terrarium and which shall imitate the light of the moon. In most cases these are blue LED, but they do not imitate real moonlight. They are much too bright compared to natural moonlight. The blue light actually belongs to the daytime spectrum, which can disturb the day-night rhythm of chameleons via the pineal gland.
If you want to get into the topic of light in the terrarium more intensively, the website of the same name by the physicist Sarina Wunderlich is very well served. Her website contains detailed explanations of all lamp variants, frequently asked questions in terraristics, differences between CCGs and ECGs, tips for measuring lamps, information on the use of UV-B measuring devices, application of the Ferguson zones, differences between frosted and clear glass bulbs and everything else concerning the topic of light in the terrarium. A big thank you to Sarina for allowing us to link her page.