UVB Light for Tortoise

While tortoises are relatively easy to care for, it is important that they have the proper set up and accessories in their enclosure. Tortoises require UV light rays in addition to proper housing and diet. While, tortoises can be exposed to UV light rays from the sun, it can be difficult if your tortoise is kept indoors. This article will discuss why you need UVB lights for your tortoise, and recommend which ones you should buy.

A complete lack of UV light can lead to illness and even death, so UVB light bulbs are essential in an indoor tortoise enclosure. Tortoises in the wild can get 8-10 hours of light per day, so you should try to replicate this in their indoor enclosures.

Best UVB light for tortoises

The best UVB light for tortoises is the Lucky Herp UVB Bulb Basking Heat Lamp. You can get it on amazon for around $20.

Why do Tortoises Need UVB Light?

Tortoises need UVB light to because it produces vitamin D and Calcium. It also helps prevent metabolic bone disease.

UVB Light Produces Vitamin D and Calcium

UVB light plays a huge role in the growth and development of a tortoise. It aids in vitamin D production, which allows tortoises to absorb calcium. Calcium, as you are probably aware, is required to develop healthy bones and a healthy shell. Without calcium, your tortoise will develop a rubbery shell and weak bones. While you can supplement your tortoises diet with calcium, they will still need the vitamin D from UVB light.

UVB Light Prevents Bone Diseases

UVB light aids in the prevention of bone diseases such as metabolic bone disease. Metabolic bone disease develops when tortoises are not exposed to enough UVB light. This can cause a stunt in growth of a tortoise shell, and in some cases can lead to shell rot. If left untreated, it can be fatal.

Signs that your Tortoise isn’t Getting Enough UVB Light

Not providing a UVB light for your tortoise can result in various health issues. Brittle bones, a weak shell, and bone disease can all occur. Furthermore, your tortoise may lose appetite and become lethargic, which can be hazardous to your tortoise’s overall health and well-being.

Types of UVB Bulbs for Tortoises

As said before, there are multiple kinds of UVB light bulbs, and it is best to understand them all to select the best option for your tortoise.

UVB Bulbs

UVB bulbs are the most common type of light that tortoise owners buy. They can be fluorescent light strips that cover a large surface area or corkscrew bulbs. The bulbs usually have a UVB rating which states the percentage of UVB light that is emitted from the bulb.

Compact UVB Bulbs

Compact UVB bulbs are smaller and typically have a lower wattage. They can be straight or coiled, but they function the same way. One disadvantage of compact UVB bulbs is that they usually don’t have a large range. Because their range is limited, you will need to move them closer to the enclosure.

Combination Bulbs

Combination bulbs, also known as mercury vapor bulbs, are excellent choices for your tortoise. These bulbs are fantastic because they emit UVB and heat at the same time. This is useful if you don’t have enough space in your enclosure to house multiple lamps for heat and UVB. However, it should be noted that these types of bulbs have been known to overheat. If you already have a basking light, you can use a tortoise heater to keep your tortoise warm.

Colored Bulbs

There are many different colored UVB light bulbs available, each with its own set of advantages. White, blue, or fluorescent lights are bright and simulate natural light that tortoises experience in their natural habitat. In contrast, black or red lights can be used at night to provide extra heat without disrupting your tortoise’s sleep and metabolism.

Now that you understand the various UVB light bulb types, here are our top three recommendations for the best UVB light bulbs for tortoises you can buy.

Best UVB Bulbs for Tortoises

The best UVB bulbs for tortoises are the Zilla Fluorescent Bulb, Reptizoo Energy Saving Lamps, and the Exo Terra Repti-Glo Terrarium Lamp.

Zilla Fluorescent Bulb

The Zilla Fluorescent Bulb is a tube-style UVB bulb that can produce 20 watts. It has a large surface area, and models are designed specifically for desert and forest species. It stimulates the natural light that your tortoise would receive outside and is ideal for building strong bones and shells. Because it is a tube-type, you will need a specialized fixture, but some stores sell both the fixture and bulb together.

Reptizoo Energy Saving Lamps

When it comes to lighting, Reptizoo is a well-known brand. As the name implies, this UVB bulb will save a lot of energy while emitting a bright white light with up to 26 watts, and the UVB ray ratio is suitable for tortoises.

It provides an adequate amount of UVB rays, which aids in the development of stronger bones and shells. It is incredibly durable, and it has a long lifespan, which means you won’t have to replace the bulb very often.

Exo Terra Repti-Glo Terrarium Lamp

The Exo Terra Repti Glo Terrarium Lamp is a compact UVB bulb that can produce up to 26 watts. They come in different varieties, one designed specifically for desert species and the other for forest species. It provides all of the necessary rays for optimal calcium absorption.

If you have a Russian Tortoise, you should check out my article on the best heat lamp for Russian Tortoises.

Other Things to Keep in Mind When Buying a UVB Light

When shopping for a UVB light bulb, choose one that emits the same amount of UVB as natural sunlight. An overpowered UVB light bulb can burn your tortoise, and in some cases, the light can burn the tortoise’s corneas.

There are several different options, but not all are high quality. It’s also worth noting that the amount of UV light rays needed by a tortoise differs based on its species. For example, forest tortoises under the canopy rarely get direct sunlight, so they don’t require a strong UVB light bulb.

On the other hand, desert or grassland tortoises enjoy basking in the sun and are thus more tolerant of higher UVB concentrations. Bearing this in view, you should do some research on your tortoise before buying a UVB light bulb. You should also check out the best bedding for tortoises.


When constructing your tortoise enclosure, make sure that you buy a bulb proportional to the enclosure’s size. Your tortoise may not be receiving enough UV light if your enclosure is too large and the bulb does not cover a large enough surface area.

In contrast, if your enclosure is too small and the bulb covers too much ground or is too close, it can cause burns and dehydration. Most bulbs should be replaced every 6-12 months, and most brands will specify how often you should replace them. UVB lights provide numerous benefits to your tortoise and are required in an indoor enclosure.

We hope this article has helped you understand the importance of UVB lights and helped you decide which one to purchase. I am confident that your tortoise will live a happy life as long as you have an effective UVB light.