Best UVB Light for Turtles (2021) | Guide and Reviews

by Carl Crane | Updated: November 21, 2021

Getting to know why lighting is essential for your pet turtle and what UVA and UVB rays actually do for them, will take you a step further in being a better reptile owner.

The lights aren’t just so we can see them better when it’s dark.

In fact, they need the right kind of lighting for each stage of their life to help them grow healthy and to maintain the right amount of nutrients throughout their day.

The two most common ways to provide light are through compact UVB bulbs and tube UVB bulbs.

The compact UVB light bulbs are usually pretty cheap and easy to find, but sometimes in the past, they have been known to cause photo-kerato-conjunctivitis and basically what that means is that this can cause some eye problem for your turtle.

Recently we haven’t heard anything about this issue since the manufacturers made some changes to the more recent light bulbs, it’s just a thing to keep in mind when considering using a compact UVB bulb.

The tube UVB light bulbs are a little bit more expensive but a little bit more powerful and they usually fit in your standard aquarium hud with them also being very safe to use for your turtle.

When purchasing the best UVB light for turtles you will need to keep in consideration some factors that will decide the health of your turtle so keep reading.

Don’t have time to read the article right now? Don’t worry, below you can find our best pick for UVB light for turtles. 

We Recommend

Why is Light Important for Turtles?

The first thing that we need to cover is that turtles are reptiles. The importance of this is that all reptiles do something called thermoregulation.

Basically, as mammals, we humans maintain our constant body temperature, however, reptiles rely on outside light sources in order to raise or lower their body temperature depending on what they need. 


They can raise their body temperature in order to increase metabolism or lower them to be more inactive.

Reptiles achieve this by moving to different areas of their surroundings to warm up or cool down.

This can be done through radiationconvection or by the evaporation of body fluids. It may be either raised or lowered by the conduction of heat to or from the substratum or the air.

– The reptile sitting on a basking spot that has been warmed by the sun/heating element glowing on it, or from within in the case of a heating pad/rock.

– The warm air/water that blows/flows across the reptile.

– The reptile absorbs the electromagnetic radiation from the sun/heat element.

What is UVB Light and Why do Turtles Need it?

The UVB light is a type of light that the sun emits and is part of the UV Spectrum. 

This UV Spectrum is broken up into 3 parts, these being the UVA, UVB and UVC lights and they can all be found in the natural sunlight.

The UV light wavelengths are filtered by plastic and glass so when setting them up for the habitat be sure they have direct exposure to the enclosure.

The UVB light helps your turtle get his vitamin D3 which also absorbs calcium. You can also expose your turtle to a UVA light as this will help him regulate his behaviors such as feeding, daily movement, and mating.

These two types of ultraviolet lights play different roles for your reptile pet and combining them will ensure him a long-lasting life.

vitamin D pathway

The pathway begins when a cholesterol, provitamin D, (7DHC) is manufactured by  the cells in the skin. When revealed to the UVB at wavelengths between 290 – 315nm, this provitamin D is converted very fast to previtamin D3.

Previtamin D3 is then isomerized (modified by a re-arrangement of atoms in the molecule) gradually, in warm skin over several hours to vitamin D3.

Heat is needed for the reaction to proceed at a normal rate. Reptiles obtain this heat from the sun or any other heating source, as they bask.

The vitamin D3 is released from the skin cell membranes and is taken up by a “vitamin D-binding protein” into the plasma.

It is therefore carried in the bloodstream from the skin to the liver, where it is hydroxylated to calcediol, 25-hydroxy-vitamin D3.

This is the substance that is tested for in blood samples taken to assess the reptile’s vitamin D status.

The 10 Top-Rated UVB Light Bulbs for Turtles

Editor’s Picks



Top Pick

Zoo Med Reptisun 10.0 UVB Mini Compact Fluorescent


Runner Up

TEKIZOO UVA UVB Sun Lamp High Intensity Self-Ballasted Heat Basking Mercury Vapor Lamp/Light/Bulb


Best Budget Buy

Zoo Med ReptiSun 5.0 UVB Mini Compact Fluorescent


Best Light Kit for Turtles

Zoo Med Aquatic Turtle UVB Heat Lighting Kit


Best Tropical UVB Light for Turtles

Exo Terra Repti-Glo 5.0 Compact Fluorescent Tropical Terrarium Lamp


Best Desert UVB Light for Turtles

Exo Terra Repti-Glo 10.0 Compact Fluorescent Desert Terrarium Lamp


Best UVB Tube Light for Turtles

Zoo Med OS36 T8 ReptiSun UVB 10.0 HO Light


Best Fluorescent Lamp UVB for Turtles

Reptisun 10.0 Uvb Fluorescent Lamp for Reptiles


Best Basking Light for Turtles

Zoo Med Powersun UV Self-Ballasted Mercury Vapor UVB Lamp


Best Mercury Vapor Light

Evergreen Pet Supplies 100 Watt UVA UVB Mercury Vapor Bulb/Light/Lamp for Reptile


*Ratings are from Amazon at the time of publication and can change

Best UVB Light for Turtles

Best UVB Light Bulb for Turtles

1. Zoo Med ReptiSun 10.0 Mini Compact Fluorescent Lamp

Size: 6″ x 2″ x 2″ | UVB: 10% Output | UVA: 30% Output | Watts: 13

The Zoo Med Reptisun 10.0 Uvb Mini Compact Fluorescent 13 Watt can be considered the safest bulb you can find in the market.

The light bulbs are of high quality and trustworthy that provides UVB, UVA and visible light, which are crucial for reptiles.

This light bulb is actually best to be used over the basking spot so the turtles can absorb the UVB and it can be used with with lf18, lf19 lf50, lf55 hoods.



2. TEKIZOO UVA UVB Sun Lamp High Intensity Self-Ballasted Heat Basking Mercury Vapor Lamp/Light/Bulb

Size: 6.3″ x 4.5″ | UVB: 10% Output | UVA: 35% Output | Watts: 160

The TEKIZOO UVA UVB Sun Lamp specifications indicate that it is designed to provide lots of UVB and enough heat, which makes it an excellent choice for one’s turtle.

Been using them for years for my turtle, no MBD (Metabolic Bone Disease) issues, I replace it every 6 months to make sure UVB is still working.

Even when the UVB expires, heat and light still work.

UVB/UVA/LIGHT/HEAT all in one single bulb, saves a lot of clutter! *Use this with a deep dome*



3. Zoo Med ReptiSun 5.0 Mini Compact Fluorescent Lamp

Size: 5.9″ x 1.6″ x 1.6″ | UVB: 5% Output | UVA: 30% Output | Watts: 13

The Zoo Med ReptiSun 5.0 Mini Compact Fluorescent Lamp 13 Watt makes it perfect for all tropical species of reptiles which can produce a good amount of UVB and UVA light.

The UVB wavelengths help prevent or reverse metabolic bone disease in captive reptiles and UVA helps to increase activity levels, appetite, and reproductive behaviors

All-in-all, this mini-compact fluorescent is great for smaller types of enclosures and should only be used as a last option.



4. Zoo Med Aquatic Turtle UVB Heat Lighting Kit

Size: 11″ x 6″ x 7.3″ | UVB: 5% Output | UVA: 30% Output | Watts: 13/ 100 | Kit: Yes

If you are looking for a 2 in 1 mini combo light solution to have both heat and UVB, UVA rays coming out from the same spot, the Zoo Med Aquatic Turtle UVB Heat Lighting Kit will take it from here with you.

This is a great kit for beginners and also for anyone else who is looking for something new to try when it comes to UVB and heat bulbs.

The dimensions are 11″ x 6″ x 7.3″ and included a 13 watt UVB bulb and 50 watt heat lamp which is rated for up to max 100 watts



5. Exo Terra Repti-Glo 5.0 Compact Fluorescent Tropical Terrarium Lamp

Size: 2.6″ x 2.6″ x 7.8″ | UVB: 5% Output | UVA: 30% Output | Watts: 13/ 26

The Exo Terra Repti-Glo 5.0 Compact Fluorescent Tropical Terrarium Lamp emits optimal levels of UVB for optimal calcium metabolism, similar to that of shady habitats such as rain forests or other tropical locations.

Turtles living in these habitats receive moderate UV radiation due to climatological conditions that prevent unfiltered sunlight from reaching the reptile’s basking site.

The advantage of this light lamp is its size and the fact that it is self-ballasted. A normal screw fitting is enough to operate these bulbs.

The bulb has a wattage of 26, and the spiral shape of the bulb permits vertical or horizontal mounting without compromising the performance.



6. Exo Terra Repti-Glo 10.0 Compact Fluorescent Desert Terrarium Lamp

Size: 2.6″ x 2.6″ x 7.8″ | UVB: 10% Output | UVA: 30% Output | Watts: 13/ 26

The Exo Terra Repti-Glo 10.0 Compact Fluorescent Desert Terrarium Lamp is ideal for all desert dwelling turtles which helps them simulate the environment of a natural desert.

This bulb has a very high UVB output similar to sunlight in deserts since these locations receive more direct sunlight, therefore desert reptiles are more exposed to UV radiation than any other type of reptile.

This bulb can also be applied on screened terrariums or terrariums with thick screen covers to ensure UVB penetration.

Dense screens can filter out up to 50% of the UVB rays. Fluorescent bulbs lose their UV radiation and approximately 50% of their lighting output quality within one year.



7. Reptisun 10.0 Uvb Fluorescent Lamp for Reptiles

Size: 6″ x 2″ x 2″ | UVB: 10% Output | UVA: 30% Output | Watts: 26

We can’t stress enough how important it is to make sure you have a good quality light for your reptile and the Zoo Med Repti Sun 10.0 UVB has it all.

Your turtle will be a totally different pet after getting this high-quality UVB light as it will prevent any metabolic bone disease, giving him at the same time the right amount of Vitamin D3.

This UVB tube light will work great with larger terrariums where greater than 12″ of UVB penetration is needed.



8. Zoo Med OS36 T8 ReptiSun UVB 10.0 HO Light

Size: 36″ x 1.3″ x 1.3″ | UVB: 10% Output | UVA: 30% Output | Watts: 25

The Zoo Med OS36 T8 ReptiSun UVB 10.0 HO Light is 25 Watt and has a cool burning that can be screwed into standard threaded sockets, eliminating the need for a separate ballast.

The lamp can be oriented either vertically or horizontally in your turtle hood and it will help prevent or reverse any metabolic bone disease while increases feeding and mating potential.



9. Zoo Med Powersun UV Self-Ballasted Mercury Vapor UVB Lamp

Size: 8.8″ x 4.4″ x 4.4″ | UVB: 5% Output | UVA: 95% Output | Watts: 100

The Zoo Med Powersun UV Self-Ballasted Mercury Vapor UVB Lamp is a great bulb. HIGHER NUMBERS ON YOUR UVB METER ARE NOT BETTER FOR YOUR REPTILE PET. In all actuality its worse. 

Too much UVB is bad and can cause eye issues and different forms of “sun poisoning” essentially. 

There’s a safe zone for UVB numbers, too low and they’re useless too high and they become dangerous.

These Zoo Med bulbs put out as much UVB as the noontime sun in the shade (and yes the suns rays are even in the shade) which is more than fine for constant exposure like in captivity.



10. Evergreen Pet Supplies 100 Watt UVA UVB Mercury Vapor Bulb/Light/Lamp for Reptile

Size: 6″ x 8″ x 6″ | UVB: 3% Output | UVA: 97% Output | Watts: 100

The Evergreen Pet Supplies UVA UVB Light Bulb 100 Watt makes the perfect all-in-one light source as it can produce UVB and UVA rays as well as heat which can produce up to 90 degrees Fahrenheit from 12 inches away.

The mercury vapor inside the bulb provides the turtle warmth and vitamin production necessary for their health.

This makes it ideal for a wide variety of reptiles which includes both aquatic and land turtles.



How to Setup the UVB Light for a Turtle Tank

Before we even talk about how to set up the lights in your turtle enclosure, we need to learn some safety-related stuff in order to protect yourself from damaging your eyes while setting up the lights in your turtle tank. 

UVA and UVB light rays are known to cause eye damage for pet owners, including cataracts and eyelid cancer so when testing out the lights in your turtle enclosure we advise to not look directly into them. 

So when setting them up in the turtle tank, set them in a way that you will not make eye contact with the light.

When setting the light always be sure you secure them tightly, especially if they are hanging right above your turtle tank.

Having the bulbs fall into the water is not ideal, since they can easily electrocute the turtle.

If you are uncertain where to put your UVB light in the turtle tank, you can always have them set up in the basking area.

Lifespan of a Light Bulb

One of the many questions we all ask ourselves when buying something expensive, is “How long will it last?” We also question, whether it is necessary to follow the manufacturer’s advice regarding the replacement of tubes every six, eight, or twelve months?

All the UVB light sources degrade over time and as the light bulb degrades, visible light output can still remain the same, but the UVB generation will begin to drop off as soon as the bulb is first switched on.

Once that happens, while the light bulb will continue to run for a certain period of time, the UVB it provides may be too low to meet the needs of your turtle.

At this point, the light bulb is serving no purpose other than providing visible light and must be replaced for the health and well being of your pet.

The rate at which bulbs will deteriorate depends hugely on the type of light bulb and how long the bulb is used every day, but will also vary among individual bulbs.




Although most of the UVB light packages state that the UVB only lasts for 12 months in the bulb we recommend replacing them every 6 to 9 months if you want to be on the safe side.

What are the Different Types of UV Bulbs?

As we’ve seen, when choosing a lamp for a turtle tank, the question we must ask ourselves is “How much UVB does my reptile need, given its natural habitat and basking preferences?

Various light bulbs vary enormously in the volume of UV light they emit, and in the kind of beam they offer.

If two lamps produce, for instance, 20uW/cm² of UVB at 12″ range, but one light has a beam that is double as wide as another, then a big reptile sitting 12″ away, which cannot sit completely inside the beam, will be able to generate more vitamin D3 from the lamp with the broader beam.It’s also very helpful to know the type of lamp we are using for our turtle enclosure and how it works:

Type of lamp

Fluorescent Light Tubes Tubes provide a diluted “glow” with low-intensity visible light, slight heat, and a reasonably uniform UVB gradient, over a proportionately large area, resembling natural UVB “in the shade” on a bright day.
Compact Fluorescent BulbsCompacts provide a more powerful UVB gradient collected in a smaller area but still provide only fairly low-intensity visible light and slight heat.
Mercury Vapor Flood LampsTrue “flood” lamps deliver a more powerful UVB gradient stored in a smaller area. These lamps also create heat and more intense visible light, but it is still provided as a thin “glow” rather than a beam.
Mercury Vapor Spot and Narrow Flood LampsBecause these have a directed beam, they deliver very intense light and high UVB concentrated like a spot of sunlight. Self-ballasted lamps produce more heat and an even more powerful visible light.

Good UVB lamps are costly, because of the quality glass, phosphors, arc tubes and so forth that go into their creation, and because many mercury vapor lamps are actually hand made.

5.0 or 10.0 UVB for Turtles

Both bulbs make the same amount of light and the 5.0 UVB bulb usually produces half the UVB that a 10.0 UVB bulb can make. 

You only want to use the 5.0 UVB bulb where you have space constraints or if you want to put it in something like a mini deep dome

For turtles and tortoises we always recommend the 10.0 UVB bulb and it must be mounted no more than 10-12″ away to get any UV benefit from it. 

No one should rely anymore on the old 5.0 and 10.0 UVB principle, as these numbers only vaguely show the UVB output of the bulb ranging between 280-320nm which is needed for the vitamin D production. 

2 in 1 Heat and Light kit

You can meet the turtle’s light needs with just one lamp. They are one of the most popular and convenient way to provide heat, daylight, UVA and UVB rays all in one lamp.

The best part is that each bulb is on a separate switch so this comes with the flexibility to choose which light you want to turn on at any time.

The 2 in 1 light and heat kits are a good option if the turtle tank is running low on space. 

They can be a bit more expensive than your average light bulb, but they will provide everything that your turtles needs.

Daytime and Night Lights

When it comes to normal light in your turtle enclosure, as long as you have a light that puts out some form of brightness your turtle won’t care and will be happy.

The turtle wants light in the tank when it’s daytime and no light when it’s nighttime. Here you can use LED lights, T5 and T8 bulbs or your standard aquarium light bulb to light up the enclosure. 

Typically you will want it to be photoperiodism, which is a fancy word for how long you will want your lights to be on. 

Turtles are also subjected to circadian rhythms. “Circadian rhythms”, in other words, means your body clock. Circadian rhythms can be mental and physical, as well as behavioral changes that follow a regular routine cycle. This is usually in response to the light in the turtle’s habitat.

Normally you will want the lights to be on for about 10 to 14 hours, and this sometimes just depends on the time of the year, but the general guideline is to have the lights on between 10 to 14 hours.

Keeping your lights switched on when it’s nighttime will greatly disrupt the turtle’s sleep, causing stress and affect its health.

For this, you will definitely want to get a light timer as this will help you so much with consistency, you won’t have to worry about flipping that on and off switch every day.

Heat Light Options for Turtles

Many turtles require basking temperatures in the 80’s and 90’s degrees Fahrenheit (26 – 32 degrees Celsius) so additional heat is required in most turtle tanks.

Heat lamps are favored over the under tank heaters heating pads because you can regulate the ambient air temperature however you wish.

There are all kinds of heat lights types for both aquatic and land turtles, but it is necessary to find out what bulb wattage the turtle enclosure needs in order to keep it at the right temperature.

Regularly the larger enclosures will need higher wattage bulbs, and the smaller enclosures will obviously need less wattage to maintain the proper temperatures.

Apart from the mercury vapor bulbs which also provide UVB waves, ceramic heat emitters and the regular reptile heat light bulbs are available in different wattages.

The ceramic heat emitters only emit heat with no light at all. These are great because they can last for a very long time, are much less delicate than the normal light bulbs, and can be used day and night because they don’t emit any light.

Usual reptile heat bulbs can emit white, red, blue and purple light in addition to the 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 red, blue or purple heat light while it’s night time.

Heating in the Basking Area

With heating for your basking area, pretty much any bulb that produces any kind of heat will work, you can use an incandescent light bulb, halogens or you can use specifically marketed heat bulbs for reptiles.

Also, make sure that you have a light bulb that can emit UVB rays since the turtle will spend a big part of this time basking and staying still.

The temperature of the basking area should at least be 10 degrees Fahrenheit hotter than the water temperature and that’s usually between 85-92 degrees Fahrenheit. 

We wouldn’t recommend anything lower than 82 degrees Fahrenheit and no higher than 96 degrees Fahrenheit depending on the turtle species.

The best way to measure the temperature of the basking area is by using an infrared laser temperature gun. Besides being useful it’s also super awesome and easy to use.

Point and shoot at the specific spot in the turtle enclosure, and it will tell you the precise temperature of the targeted area.

Turtle Basking Temperatures

Click Here to See Top Infrared Temperature Measurer According to Amazon >>

Heating in the Turtle Tank

Any standard glass aquarium heater will work, and the size of the heater for your tank should be 2 or 3 watts of energy times the amount of gallons in your tank.

For the temperature of your water that you will be setting the heater depending on two things: the age of the turtle and the species of the turtle.

General temperatures you will want the water to be at depending on your turtle:

You have to remember that turtles are reptiles so they do regulate their body temperature based around them, so it’s important to get the water temperature right.

A heater guard is also a good idea to have if you do happen to have it exposed for the turtle.

Click Here to See Top Heater Aquarium Guards According to Amazon >>

Commonly Asked Questions About Turtle Lighting

Q: What’s The Best Turtle Basking Light Wattage?

A 50, 75 or 100 watt light bulb will do just fine. What’s important is that the turtle’s basking area (for most general species) should be between 85 to 90 degrees Fahrenheit or 29 to 32 degrees Celsius.

Q: Do All Turtles Need A Heat Lamp?

Not every species of turtles bask, so not all of them will require a heat lamp, but all of them will need a UVB light source.

Q: How Far Away Should The UVB Light Be From A Turtle?

The general distance is somewhere between 8-15 inches, nonetheless, you will need to check the instruction manual on any light bulb you buy as well as manually take the temperature of your basking area using a thermometer.

Q: Can A Turtle Get Too Hot Or Cold?

Yes, a turtle can get too hot or too cold:

Q: For How Long Should A Turtle Basking Light Be On?

Somewhere within 10 and 14 hours should be fine.

Q: Can I Use A Regular Light Bulb For My Turtle?

No, if you intend to use it to provide your turtle with UVB and UVA lights.

Regular light bulbs don’t provide any UVA, UVB light and can be used to only provide the necessary light during the day time to maintain their circadian rhythm.

Q: Do Turtles Need A Heat Lamp At Night?

You don’t have to keep the heat lamp on throughout the night. You should try to keep the heat lamp on for the same period the sun is up.

Q: Do Turtles Need Light At Night?

Having some heat is important for hatchling turtles, who often rest on the basking area at night.

Adult turtles don’t need night lights, and turtles don’t care whether they’re blue or red as long as they’re not too bright.

Q: What Wattage UVB Bulb For A Turtle?

A lamp that provides UVB light that has between 13 and 26 watts its ideal for this kind of lighting. For heating lamps having a 75 watt bulb should be the enough for most turtles at the basking end of the turtle setup.

Q: How To Keep A Turtle Warm Without A Heat Lamp?

If the room temperature is at least 75 degrees Fahrenheit, the water temperature will also have the same temperature.

A submersible water heater is necessary to avoid respiratory infections.To keep warmth in the turtle enclosure you should keep most of it covered, especially at night (make sure that there are places for air to get in).

Aside from the necessary water heater, you will have to search for a way to keep the air in your turtles tank warm.

​Our Final Thoughts

There are various different sources to obtain UV lights for your turtle as described in our article.

However, even though it may be very difficult and inconvenient to regularly let them be exposed to the natural sun, we highly recommend getting your turtle outside for even just an hour a week to get some natural UVA and UVB rays.

The most effective heat bulb is for free, and that is the sun.

Carl, the reptile-obsessed creator of this website, got his first turtle years ago and he made a ton of mistakes along the way. His goal now with TheCritterCove is simple: help others to not make the same mistakes that he did!