Pet tortoises and turtles of all kinds need the same types of lighting. Heat bulbs and UVB bulbs are both vital to properly care for your pet turtle or tortoise. If proper temperatures and lighting are not provided your pet is at risk for developing serious health problems.
Do I Need UVB Lighting for My Tortoise or Turtle?
This is, unfortunately, the most commonly forgotten part of a turtle or tortoise habitat. Many people opt not to buy the most expensive piece of a set up when they purchase their pet reptile from a pet store. These same people also tend to depend on the pet store associate to help them buy what they need for their new tortoise or turtle, and unfortunately, they are often told that UVB lighting is not necessary.
Without UVB lighting your tortoise or turtle can and will develop metabolic bone disease, be unable to synthesize Vitamin D (which causes calcium metabolism problems), be lethargic, and have a lack of appetite. UVB lighting is very important for these reasons.k
Providing UVB Lighting to Turtles and Tortoises
Natural sunlight emits invisible UVB rays in the wild, but many turtles and tortoises are housed indoors, causing these rays are blocked by window glass. Artificial UVB rays are delivered to your pet tortoise in an indoor enclosure through the use of special reptile bulbs. These bulbs run out of UVB rays about every six months, so they do need to be changed regularly.
UVB rays must also be able to reach your tortoise or turtle without being scattered or blocked by glass, plexiglass, or screens. An ideal distance between your pet and a regular UVB light is 10-20 inches, depending on the wattage of the bulb, with nothing in between them and the light. A mesh screen is okay to set your UVB light on, but it does decrease the amount of invisible rays that will penetrate through to your tortoise or turtle.
Some owners mount the UVB light fixture on the inside of the enclosure, while still keeping it 10-12 inches from the pet, to avoid a screen top from filtering out the light. The distance of this light is very important. A UVB light that is too close will cause thermal burns, much like a tanning bed would, but a light that is too far away won't do much good at all because there won't be enough UVB rays that reach your pet.
UVB Light Options for Turtles and Tortoises
The most traditional type of UVB light is the fluorescent strip light. This special bulb designed for reptiles looks like any other fluorescent bulb that you'd find on the ceilings of most any school or place of business, but it can be a UVB light. Be sure to confirm that the strip light emits UVB rays. Regular fluorescent lights do not emit UVB rays.
The compact fluorescent UVB bulb looks like a corkscrew or has a few small fluorescent tubes that create the bulb. This bulb is good if you don't have the right fixture for a fluorescent strip light, but you do have an extra clamp light laying around. The downside to these bulbs is that it only covers a small area, unlike an 18-inch or 36-inch long strip light.
Mercury vapor bulbs are more expensive but typically last longer, are much more powerful than other UVB bulbs, and also emit heat. These are great for large enclosures or entire rooms that house larger tortoises.
Heat Light Options for Turtles and Tortoises
Many tortoises and turtles require basking temperatures in the 80s and 90s, so supplemental heat is needed in most enclosures. Be sure to check what your specific species needs for heat. Heat lights are preferred over under tank heaters, because you can control the ambient air temperature. Under tank heaters often have little or no settings to control the heat and primarily warm the bottom of the enclosure while failing to warm the ambient air temperature, making achieving a proper thermal gradient difficult.
There are a variety of heat lights for tortoises and turtles, but it is important to find out what bulb wattage the enclosure requires to keep it at the desired temperature. Usually larger enclosures will need higher wattage bulbs, and smaller enclosures will naturally require less wattage to maintain appropriate temperatures.
Aside from the mercury vapor bulb which also provides UVB rays, ceramic heat emitters, and regular reptile heat light bulbs are available in various wattages. Ceramic heat emitters only emit heat, no light, and screw into a clamp light. These are great because they last a long time, are less fragile than the light bulbs, and can be used day or night since they don't give off any light. Regular reptile heat bulbs can emit white, red, or blue/purple light in addition to heat. White heat light bulbs should only be used during the day so you don't stress your tortoise or turtle out, but you can switch over to a red or blue/purple heat light at night.
Metabolic and Endocrine Diseases of Reptiles. Merck Veterinary Manual.