There are several lighting options available and your choice will likely be determined by cage design and personal preference. Cage lighting is considered optional by many, and some keepers only provide ambient light from a window, or a main room light on a timer. Regardless, as an equatorial species chondros should be provided an annual photoperiod of 12 hours of light and 12 hours of darkness. The only exception is when photoperiod is altered during breeding season as a means to encourage reproduction. There are differing accounts on the efficiency of this technique, and most breeders do not stray from an annual 12/12 photoperiod.
Lighting can be helpful even if it isn’t always used. For example, cage lighting assists in effectively monitoring your animals’ health and helps to ensure efficient cleaning. For those who choose cage lighting, 12-18 inch fluorescent under counter lights are common. These fixtures are relatively inexpensive but might require more frequent replacing due to exposure to high heat and moisture. If you decide to use fluorescent lighting, keep in mind that they emit heat and may influence your cage’s heating dynamics. As mentioned, an IR temp gun will greatly assist as you fine-tune the placement of lighting.
Recently, LED lights are being used because they emit less heat, are more energy efficient, and bulbs tend to last longer. Some keepers that use florescent fixtures are simply replacing expired fixtures or burnt out bulbs with LED light strips. The brand TrueLumen LED Strips are available in five color spectrums for freshwater and marine aquariums, and they are waterproof. They are not cheap, costing around $50 dollars/strip plus $12.00 for the power supply, but they might be more cost effective in the long run as they won’t need as frequent replacing. There are other LED strip options that are less expensive but may or may not be water resistant, so read the fine print before purchasing. Also, many of these LED strips are low voltage (12VDC) and require a transformer to be plugged into household electrical outlets.
A. Full Spectrum lighting
Full-spectrum light is light that covers the electromagnetic spectrum from infrared to near-ultraviolet, or all wavelengths that are useful to plant or animal life. Sunlight is considered full spectrum, although the solar spectral distribution reaching Earth changes with time of day, latitude, and atmospheric conditions (http://en.wikipedia.org/wiki/Full-spectrum_light).
"Full-spectrum" is not a technical term when applied to a light bulb, but rather a marketing term implying that the product emulates natural light (http://en.wikipedia.org/wiki/Full-spectrum_light). Full spectrum, or daylight bulbs, typically fall in the 5100k to 6500k range of the Kelvin temperature scale. These bulbs seem to show off an animal’s true colors best. If you have live plants in your enclosure, bulbs in the 6100k to 6500k range promote better growth. These bulbs can be found in both fluorescent and LED. Most bulbs labeled “Full Spectrum” emit little if any UVB.
B. Ultraviolet (UV) Lighting
It is commonly thought that snakes and many nocturnal lizards only require enough light to provide a day/night cycle. Furthermore, it is assumed they do not require UV light to synthesize vitamin D3 in order to survive in captivity. Also, many people feel that snakes receive virtually all of their calcium and vitamin D requirements from their diet. However, a good question might be, “Will they benefit from it if provided" as opposed to, “Can they be kept without it?”
For millions of years reptiles have lived in a world in which UV-A, UV-B, and visible light are all around them. Different species have evolved in ecological niches with behaviors (such as basking preferences) and body characteristics (such as thick or thin skin, heavy or light pigmentation) to enable them to efficiently utilize the UV-B available to them. With very few exceptions, in the wild both nocturnal and diurnal snakes are exposed to various amounts of UV light. The long-term health effects of removing this element of their natural environment are still unknown. In recent years, some keepers have added UV light to their enclosures in hopes of adding another piece to the chondro husbandry puzzle. However, more research is clearly needed before scientifically significant conclusions can be made.
When considering UV light in nature it is important to realize that no reptiles bask all day. You must consider the microhabitat for every species. For example, reptiles often make use of both sun and shaded areas, and some may never be exposed to full direct sunlight. So if you decide to experiment with UV lighting, situate the bulb where it will create a light gradient; some areas of the cage receive full exposure to the light, while other areas receive less exposure. A light gradient will allow an animal to move in and out of the “sun” as needed. Be sure to create an environment where your animal has options.
Since the use of UV light is largely uncharted territory for GTP husbandry, caution should be exercised. Make sure you don’t use a bulb that is too strong. It might be a good idea to begin providing minimal exposure and then gradually increase it over time. This can be accomplished with a timer. Since the amount of UV that is beneficial vs. hazardous is unknown, if you choose to use UV light it is strongly recommended to heavily research this topic prior to initiating a UV regimen. Also, you will clearly need to monitor your animal(s) very carefully to make sure there are no detrimental effects.