Do You Know the Importance of UVB Light for Reptiles? We Explain Some of the Key Features for Maintaining an Optimal Terrarium for Your Exotic Pets

Reptiles, like all animals, need ultraviolet light (UVB) to activate the precursor of vitamin D found in their skin. Vitamin D plays a fundamental role in calcium metabolism. When kept in captivity, reptiles don’t have access to the natural UVB light provided by the sun, so we must offer it to them artificially, as this type of radiation doesn’t penetrate glass or plastic effectively.

In the market, there are numerous types of bulbs for this purpose. Consider the size of the terrarium and the requirements of the reptile based on its natural habitat. It’s not the same for a desert reptile as it is for one from a humid jungle. Temperature is another essential factor for the animal’s proper development. Reptiles are cold-blooded animals (poikilotherms), which means they depend on a heat source to regulate their body temperature and carry out all metabolic functions properly.

As sources of ultraviolet light, there are fluorescent tubes, compact fluorescents, mercury vapor bulbs, and metal halide bulbs (HID).

Material Needed for Caring for Your Reptile
UVB Light for Reptiles
Fluorescent Tubes
These emit white light, offer different levels of UVB light, do not emit heat, and have low energy consumption. They need to be adapted to a fluorescent socket. According to the manufacturer, they should be changed every 6 months, but our experience shows that they stop emitting UVB light long before that and need to be placed very close (10-20 cm) to the animal to provide the right amount of UVB light.

Mercury Vapor
These emit yellowish light, which is less visible. They provide a good proportion of UVB light for reptiles and emit heat, but it’s not concentrated in one spot, leading to some heat loss (infrared radiation). They have higher energy consumption, and the radiation provided is good at a maximum distance of 40 cm from the animal (depending on the bulb’s power). They are connected to a ceramic socket.

HID (Metal Halide)
These emit white light, offering a broad spectrum of visible light and an excellent proportion of UVB light for reptiles. They concentrate heat in one spot. This system has fewer losses and is more efficient. Energy consumption is very low relative to the intensity of light and heat it provides, and the radiation is very good at a medium distance of 40 cm from the animal (depending on the bulb’s power). It requires a ballast (transformer) for operation.

Heat Sources
There are also various heat sources, such as heating mats, heating cables, infrared bulbs, basking spot bulbs, and the combination of UVB light with heat provided by mercury vapor bulbs and HIDs. In our opinion, the best heat sources are those that provide it from above, which is closest to how the sun does it naturally.

Heating Mats
These are placed outside the terrarium, either underneath or on the side (some have an adhesive layer and can be applied like a sticker on the side). There is a risk of burns if the animal moves the substrate and comes into direct contact with the glass. If the substrate layer is too thick, the heat provided may be insufficient. Many different models of various sizes and intensities are available to adapt to the animal’s needs.

Heating Cables
These are placed inside the terrarium, and the substrate is placed over the cable. Since they are inside, there is a greater risk of the animal coming into contact with the cable and getting burned or biting it. There are models of different intensities and lengths to adapt to the reptile’s requirements. It’s a good heat source if used correctly.

Infrared Bulbs: There are two types, one emitting red light (which can be annoying) and ceramic bulbs that only produce heat without any light. Ceramic bulbs are a good option for providing nighttime heat.

Basking Spot Bulbs: These are bulbs that provide visible light and heat. They are a good source of daytime heat when combined with UVB fluorescent bulbs.