Best UVB light for turtles

Turtles require a stable and comfortable environment to thrive and live happily. However, with the myriad of options available in the market, it is more difficult now to choose the best UVB light for your turtle.

The lighting in a turtle’s habitat is crucial to their survival. By understanding what the UVA and UVB lights do for them, you are sure of becoming a better pet turtle owner and giving them the specialized care they deserve. Not only does lighting help in helping us see them, but it is also essential in the various life stages of a turtle. Luckily, this guide will help in breaking down the role of lighting in a turtle’s habitat as well as the best UVB light for turtles.

Some interesting facts about turtles

Turtles are reptiles, which are cold-blooded animals. They require thermoregulation that aids in lowering or raising their body temperature. As mammals, humans can regulate and maintain constant body temperature without any help from external light sources.

Reptiles change their body temperature by moving around to different locations to either cool down or warm up through convection, radiation, or evaporation of their body fluids. They change their body temperature through conductive heat, which implies heat transfer between two objects that are in contact with each other or within an object. They also utilize radiant heat, which involves the flow of thermal energy through electromagnetic waves. For instance, when a reptile basks in the sun, it is absorbing radiant heat.

These cold-blooded animals can also raise or lower their body temperature through convective heat that usually involves absorbing heat from movement f water or air. For instance, if warm winds blow against a reptile, likely, its body temperature will also warm up.

What is UVB lighting, and why do turtles need it?

As part of the UV spectrum, UVB light refers to a type of light emitted from the sun. The UV spectrum consists of three parts; EVA, UVB, and UVC, all of which are in natural sunlight. UVA and UVB lighting play a crucial role in the growth and development of your reptilian pet to ensure they have a long-lasting and happy life. UVB light aids your pet turtle in acquiring vitamin D3, which helps in the absorption of calcium. The UVA light assists in regulation behaviors such as feeding, mating, and daily movement.

When your turtle ingests cholesterol, the cells in its skin manufacture provitamin D. Upon exposure to the UVB light at wavelengths of 290-315nm, provitamin D converts to provitamin D3, which is then isomerized through the re-arrangement of atoms in the molecule in the warm skin and becomes vitamin D3.

Usually, reptiles absorb much heat from the natural sunlight as they bask. Their skin membranes release vitamin D3 and a vitamin B-binding protein takes it into the plasma. It is then absorbed into the bloodstream and transported from the skin cell membrane to the liver, where it is hydroxylated to 25-hydroxy-vitamin D3, also referred to as calcidiol, the substance extracted from reptiles to assess their vitamin D status.

Alternatively, if a turtle does not absorb sufficient UVB light, it is unable to process and use calcium in their bodies. As such, they may experience limited growth of their shell or shell decay, limited boned growth or bone decay, and even premature death in extreme cases. Therefore, you must purchase a specifically-designed bulb for reptiles and not just any old fluorescent lamp. The bulb must have the ability to produce both UVA and UVB light, as they are vital in the survival of your shelled pet.

Factors to consider when buying a UVA/UVB light

As discussed above, UVB light aids in keeping your turtle strong and healthy by helping it form a strong shell and bones. Generally, the proper care of a turtle involves providing it with a proper diet, an adequately-sized tank, a basking area, clean filtered water, and UV lighting.

With numerous UV lighting options, you have to be careful about the type of lighting source that you choose. You cannot use an ordinary light bulb as it can only give your reptilian friend heat but not UVB lighting, which is vital to their health. Turtle owners who use regular incandescent light bulbs only use it for warmth and ensure that there is another reliable source of UVB light.

When choosing UVB light, some crucial considerations to make include:

Does the light bulb produce UVB light?

There exists a wide variety of light bulbs in the market. When buying a light source for your pet, you must ascertain that it produces UV light, and it is not a regular light bulb. Similarly, different light bulbs vary in the volume of UV light they emit, and in the type of beam they offer. You may opt for a fluorescent light tube that provides a diluted ‘glow’ with a visible, low intensity and reasonable UVB gradient light. On the other hand, you may choose a mercury vapor flood lamp that delivers a more powerful UVB gradient over a smaller area and create a more intense and visible light with more heat than the latter.

It is upon you to figure out which light source is most suitable for your turtle’s set up and how much space you have. In case of limited space, the 2 in 1 light kit is an excellent choice as it offers UVB and UVA rays, provides daylight, and heat, all through one lamp. They are slightly more expensive than your average UVB light source but well worth the extra coins as they provide your turtle with all that it needs.

The lifespan of the light source

Over time, every UVB light source degrades, and its visible light output can remain the same throughout. Once the UVB light source begins to deteriorate, its UVB generation starts to drop as soon as you start using it. As such, the strength of the UVB light it produces continuously drops until it is too low to meet the needs of your pet turtle, meaning you must replace it as soon as possible.

The rate at which a UVB light source degrades depends on how long it is used daily and the type of light bulb it contains. Generally, most UVB light source packages last for only 12 months, but it is advisable to replace them every six to nine months to be on the safe side.

The wattage of your light source

You must provide your reptilian pet with the right temperature inside its habitat. Your light source’s wattage depends on the number of turtles in the tank, the tank’s size, and the size of the basking area. Generally, most turtle species prefer a temperature of 85-90 degrees Celsius in their basking area. Most turtle owners use a 50, 75, or 100-watt light source.

The age of your turtles also helps in determining the strength of your light source. A baby turtle requires 78-80 degrees Fahrenheit, while a juvenile turtle prefers water temperatures of 75-78 degrees Fahrenheit. Similarly, adult turtles need 72-75 degrees Fahrenheit to thrive and live healthily. Keep in mind that turtles are reptiles, and they regulate their body temperatures based on their surroundings. As such, it is essential to get their water temperature correct.

The best UVB light for turtles

Name of product
UVB output
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Repti-Glo Compact Fluorescent Tropical Terrarium Lamp by Exo Terra
Zoo Med Aquatic Turtle UVB Heat Lighting Kit
Reptisun 10.0 UVB Fluorescent Lamp
Evergreen Pet Supplies 100W UVA/UVB Mercury Vapor Lamp for Reptiles
Zoo Med Reptisun 10.0 UVB Mini Compact Fluorescent

The best UVB light for turtles should be one that produces both UVA and UVB lighting, as well as some heat to the turtle’s environment. This light source should replicate the role of the sun in as much as it possibly can. Here is a list of some of the best UVB light that replicates the sun entirely.

Repti-Glo Compact Fluorescent Tropical Terrarium Lamp by Exo Terra

The Repti-Glo 5.0 Compact Fluorescent Tropical Terrarium Lamp from Exo Terra releases optimal levels of UVB light for maximum calcium metabolism, as seen in shady habitats, such as those in the rainforests and other tropical locations. Turtles under this lamp obtain adequate UV radiation due to the climate-related factors that prevent unfiltered sunlight from reaching the turtle’s basking site.

This light lamp is of regular size, meaning that a standard screw fitting is enough to fix it within your reptile’s habitat. The lamp is also self-ballasted and has a wattage of 26. Its spiral shape permits horizontal or vertical mounting without compromising its effective performance.


  • Suitable for all tropical and sub-tropical reptiles
  • Ideal for using at a distance of up to 12” (30cm)
  • Provides optimal levels of UVB light as it replicates natural sunlight


  • The longevity of this lamp is questionable


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Zoo Med Aquatic Turtle UVB Heat Lighting Kit

If you are looking for a versatile 2 in 1 light solution to provide your turtle with both UVB/UVA Light and heat from the same source, the ZooMed Aquatic Turtle UVB Heat Lighting Kit is a perfect choice. Not only is it a fantastic kit for beginners, but it also comes with a 50-watt heat lamp and a 13 watt UVB lamp.

With dimensions of 11″*6″*7.3″, this lighting kit has a double fixture with two lighting bulbs that are excellent for when you want to change moods in your reptile’s tank. The kit also comes with an on/off safety switch and ensures your turtle is both healthy and happy in the long run.


  • Dual ceramic sockets that are safe for use with lamps of up to 100 watts
  • Deep dome surface that extends beyond the lamp’s face to prevent the lamp from ‘bulging out’
  • Polished aluminum dome surface that increases UV and light output to 30%


  • Its bulbs are weak for larger tanks


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Reptisun UVB Fluorescent Lamp

With the Reptisun UVB Fluorescent Lamp for reptiles, your pet turtle receives a cool burning screwed into threaded sockets; thus, doing away with the need for a separate ballast. You can fix the lamp either horizontally or vertically in your turtle’s tank, depending on your preference and design of the tank. With this light source, you are sure to reverse and prevent any metabolic bone disease while increasing mating and feeding potential in your shelled pet.


  • Ideal for all basking and desert reptiles
  • The lamp produces 30% UVA output, 10%UVB output
  • Offers maximum UVB penetration through the use of a special UVB transmitting quartz glass


  • The bulb is long, meaning you will need a deep dome


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Pet Supplies 100W UVA/UVB Mercury Vapor Lamp for Reptiles from Evergreen

The Pet Supplies UVA/UVB 100W light bulb from Evergreen is the perfect all-in-one light source as it produces heat of up to 90 degrees Fahrenheit at a distance of 12-inches away and also produces both UVA and UVB light rays. The lamp’s bulb contains mercury vapor that provides your pet turtle with vitamin production and warmth, which is necessary for their health. As such, this lamp is suitable for both land and aquatic turtles.


  • It is a powerful source of UVA/UVB light and heat
  • Excellent daylight bulb for your shelled pet
  • You can use it for ten months efficiently until its UVB output fades


  • It is a better source of heat as its UVB output is quite low


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Zoo Med Reptisun 10.0 UVB Mini Compact Fluorescent

Popularly considered as the safest light bulb available in the market, the ZooMed Reptisun 10.0 UVB Mini Compact Fluorescent bulb is a high-quality light source that produces UVA and UVB light, as well as visible light for your pet turtle. It is most suitable for use over your basking spot to allow the turtle to absorb UVB light effectively.


  • Affordable as it is available in packs of two, four, and six
  • Allows maximum UVB penetration due to its use of a special UVB light-transmitting quartz glass
  • Many people consider it the safest bulb in the market


  • It is too long, and many clamp lights cannot shield or hold the entire bulb due to their shallowness


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With different sources to obtain UV light available, there is no excuse for not allowing your pet to get sufficient UVA/UVB light. Keep your pet comfortable and healthy by ensuring that it absorbs optimal UVA/UVB light now and then. It is also advisable to take your turtle outside to absorb natural light at least for an hour per week. Remember that the most efficient heat bulb is free, and it is readily available; that is the sun.

Kerry Blake

Since I was young, I have always had a thing for sea creatures. Being raised along the beach gave me the chance to interact with all kinds of reptiles, including turtles. I have always found this creature quite fascinating, and at a young age, I asked my parents to get me one as a pet. My love for turtles is what inspired me to pursue marine science when I got to college. Specializing in this field made learning so much about such reptiles. If you would like to get a pet turtle at your home, this guide will be of great help.

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