Do Turtles Need UVA or UVB?

Do Turtles Need UVA or UVB

Proper lights are very important for your turtle’s health. Hence, setting up a good lighting and heating system is necessary for the turtle tank. In the wild, turtles rely on sunlight for heat and the ultraviolet rays that provide them with vitamin D3.

It is also equally important to know the temperature requirement of your turtle. Excess heat can harm your turtle than do any good. While sunlight is the best source of light for the turtle, you can also use bulbs or lamps to provide the required amount of heat to them.

When kept in captivity, heat lights are essential for the turtle’s survival, but do they need the UVA and UVB lights to survive? Many of the turtle owners must be having this question, and hence we have come up with all the details you need to know in this article.

Related Article: How To Keep A Turtle Warm Without A Heat Lamp?

Do turtles need UVA or UVB?

Turtles need both UVA and UVB lights for their good health. UVA lights provide them with warmth. It helps them maintain the correct body temperature to regulate their metabolism, breed, and support their immune system. UVB light helps them to produce vitamin D3. This vitamin is necessary to metabolize calcium which helps their shells and bones grow stronger.

Most turtle owners think that the UVA light is not as important as the UVB light, but it is not true. UVA light helps the turtle with breeding and other activity levels. The turtle that lives in the wild are exposed to UVA rays every day, and to create a similar environment like wild for them, you need to provide them with UVA rays.

UVB light is vital for turtles’ growth. It helps the turtle to metabolize calcium. Calcium is an essential mineral for turtles and is the most important part of their diet. When their skin absorbs UVB rays, the body creates vitamin D and converts it into vitamin D3. This vitamin helps them to utilize the calcium they have taken through food.

What kind of lights do turtles need?

Turtles need UVA, UVB, and heat lights to stay healthy and strong. Lights help to regulate turtles’ circadian rhythms. They need periods of day and night to function properly.

If the circadian rhythm of the turtle is disrupted, they are not able to sleep, which can cause them to become stressed. It also impacts their immune system and overall health. It’s recommended to leave the lights on for eight to ten hours a day and turn them off for ten to twelve hours during the night.

In the wild, they get heat from the sunlight to regulate their body temperature. As a turtle owner, you need to replicate natural conditions your pet would have in the wild. UVA, UVB, and heat can be provided to your turtle through special lamps.

Most lamps available in pet shops are designed to provide UVA and heat. However, they don’t provide UVB lights, and hence you need to purchase a separate one for UVB. 

Some mercury vapor lamps are available online, which are designed especially for turtle tanks to provide UVA, UVB, and heat light all in one lamp. Here is our recommended mercury vapor lamp that you can purchase: 

Image Product Price Purchase Link
evergreen-lamp Evergreen UVA UVB Mercury Vapor Bulb (100 Watt) $27.99 Buy on Amazon
tekizoo-lamp TEKIZOO UVA UVB Sun Lamp (80 Watt) $26.96 Buy on Amazon

The other lamps that you can use for your turtle are:

Image Product Price Purchase Link
zoo-med-combo Zoo Med Basking and UVB Lamp Combo $24.14 Buy on Amazon
iootasea-lamp IOOTSEA UVA+UVB Lamp With Adjustable Holder (2 halogen lamp) $19.99 Buy on Amazon
MCLANZOO-UVA MCLANZOO Reptile Heat UVA Basking Lamp (2 Pack) $16.99 Buy on Amazon
we-charger-UVA We Charger Heat UVA Basking Lamp (2 Pack) $15.99 Buy on Amazon

To know more about which lights to use for your turtle, you can read our article: Can I use a regular light bulb for my turtle?

Does Box turtle require UVA and UVB lights?

Yes, Box turtle requires both UVA and UVB lights. UVA lights play an important role in a box turtle’s mental health. UVB lights are important for them to generate vitamin D3.

In the wild, box turtles absorb UVA lights from the sun. But in captivity, you should make sure that they get enough UVA rays. Box turtles feel happy and healthy when they are exposed to UVA rays. They get the required warmth from the UVA rays. If they do not get enough UVA rays, they might get stressed out or stay alone in the corner of their enclosure, feeling unhappy. 

Hence it is essential that, along with UVB lights, you also provide them with UVA lights. UVB lights process vitamin D3 in Box turtles. They have a chemical in their skin which is called dehydrocholesterol or 7DHC. UVB rays turn dehydrocholesterol into vitamin D, which helps the box turtle keep bones, shells, and skin healthy. If they don’t get UVB rays, they can suffer from shell diseases such as metabolic bone disease.

How much UVB does the turtle need?

The amount of UVB your turtle need depends on its habitat. Most turtles require 10.0 or 10% UVB, especially turtles who live in desert conditions. However, aquatic turtle species need less UVB, around 5% or 5.0 bulb.

UVB lights do not penetrate glass, and hence your turtle in a sunny window will not get the full spectrum it needs. You can hang the UV lights twelve to fifteen inches above the top of your turtle’s shell. A bulb emitting three to five percent UVB left on for ten hours a day will gradually decrease its effect after ten months.

When you are using UVB lights above the turtle’s basking area, keep a timer so that the light remains on for 10 hours daily. The light should be kept on in the basking area at a temperature of 80 degrees Fahrenheit. Replace the lights twice annually because the UVB lights lose their effectiveness with time.

If the turtle gets too much UVB light, it will move away from there and try to cool itself off by swimming in the water. The turtle does this to regulate its body temperature. But if your UVB light is positioned too close to your turtle basking area, it may cause damage to your turtle’s eyes. Hence you need to keep it at least 8 inches above the basking spot.

Most turtles require 85 to 90 degrees Fahrenheit temperature in their basking spot. The wattage corresponding to this temperature range is around 50 to 100 watts. If your UVB lamp produces less than this, you will require a heat lamp to achieve the correct basking temperature.

How to keep yourself safe from UVA, UVB, and Heat lights?

Never try to look directly into the UV lights. The UV lights can damage your eyes. Make sure the hooks, clamps, or hinges that you use are strong enough to support your lights. If you see any light fallen inside the tank, do not directly put your hand inside the tank without unplugging the live wires. Ensure that you have unplugged all wires before sticking your hand inside the tank.


Turtles need both UVA and UVB light to remain strong and healthy. UVA lights provide them with warmth. It helps them maintain the correct body temperature to regulate their metabolism, breed, and support their immune system. UVB lights help process vitamin D3, which helps them metabolize calcium inside their body. In the wild, turtles absorb the sunlight to gain the required heat, UVA, and UVB for their survival. In captivity, you need to make a similar environment for them by using appropriate UVA, UVB light, and heat lamps.