Do Turtles Need UVB Light? (Beginners Guide)

Turtles are fascinating creatures that have become popular pets for many people around the world. However, owning a turtle is not as simple as just providing them with food and water. One of the most important aspects of turtle care is providing them with the appropriate lighting, which includes UVB light.

Turtles need UVB light in order to get Vitamin D3, which plays an important role in the health and development of the shell, and the overall bone structure of the turtle. As pets, turtles get their UVB rays, from the UVB bulb in the basking area.

But simply having a UVB bulb is not enough, there are dangers in having both too much light, and not enough. So let’s have a look at what will happen in each case, and then see exactly how you should choose your UVB light and how to position it correctly.

What Happens if Your Turtle Doesn’t Get Enough UVB Light

UVB light plays a vital role in the production of Vitamin D3, which is essential for the calcium in the body. Without UVB light turtles won’t be able to get the proper amount of calcium which can lead to improper bone growth, metabolic bone disease, softshell, she’ll rot, and many other bad things.

What Happens if Your Turtle Gets Too Much UVB Light

If a turtle is exposed to too much UVB light, this can lead to skiing and eye irritations, which at first will only be minor inconveniences but over time they will become more serious up to the point where they will cause permanent damage.

Most turtles will try to avoid an area with too much UVB light, but since the basking area also provides heat, they won’t be able to heat themselves properly, which can also lead to numerous health problems.

So, no matter if your turtle chooses to endure the strong UVB light, or leaves when it can’t stand it anymore, the results won’t be good. So it’s important to have just the right amount of VB light in your basking area.

How to Get the Right Amount of UVB Light for Your Turtle

UVB light is produced by UVB bulbs, and each bulb will have a certain power that will come from the wattage of the bulb.

UVB bulbs don’d come with standard wattages like heat bulbs, so every bulb is slightly different, and it will produce a different amount of UVB light. So in order to find the right one, you will have to look closely at the box and see what the manufacture says, if it says anything at all. Some small manufacturers don’t provide any details at all, neither on the box nor on their website. So I will recommend you to stay away from those UVB bulbs.

I, for one, have been using ReptiSun bulbs for as long as I can remember. They are a well established manufacturer, and have been on the market for decades, and you can find their products in most, if not all pet shops, online or physical.

So, for UVB bulbs, I am going to give you the exact distance for a few bulbs that I’ve used before, and I will provide links to Amazon, where you can get them.

Zoo Med
UVB Bulb	Distance
ReptiSun 5.0 Mini CFL	5 inches
ReptiSun 5.0 CFL	7 inches
ReptiSun 10.0 Mini CFL	7 inches
ReptiSun 10.0 CFL	10 inches
ReptiSun 5.0 T8 Linear	6 inches
ReptiSun 5.0 T5 Linear	8 inches
PowerSun 80W	7 inches
PowerSun 100W	10 inches
PowerSun 160W	22 inches

And in case you have something between the UVB bulb, like a net, or a grill, you want to move the bulb closer by one inch, as anything in between the turtle and the bulb will reduce the amount of UVB rays.

One more thing to keep in mind is that UVB bulbs will stop producing UVB rays, way before they will stop producing light. On average, I would say that a UVB bulb only produces UVB rays for only half of its lifespan. I measured the amount of UVB light produced by the bulbs and noticed that after about 6 months, the amount drops considerably, so I change my light bulbs at around 6 months, and I would advise you to do the same.

And if you want to measure how much UVB light your bulb produces, you can use this device. While it’s a little bit expensive, overall it will save you money since you will know exactly when the bulbs run out of UVB light, and it will help your turtle remain healthy. But it’s not a requirement.

Besides UVB Light, Turtles Also Need Heat

Turtles need two distinct bulbs in their basking area, one that produces UVB light, and one that produces heat.

Fortunately, it’s much simpler to choose a heat bulb than a UVB bulb, since heat bulbs come in a standardized power scale, no matter the producer. All you have to do is to chose ther right one.

So let’s figure out what is the best wattage for you.

In order to give an answer that will fit your setup and your turtle, we need to know two things.

The first is what temperature you can expect from a light bulb at certain distances. And second, what turtle species do you have.

Now, let’s start with the first.

Here is a chart that I made showing what temperature you should expect to achieve using different powered light bulbs at certain distances.

50 Watts	75 Watts	100 Watts	150 Watts
Distance	Temperature	Distance	Temperature	Distance	Temperature	Distance	Temperature
4 inches	104°F	4 inches	120°F	4 inches	131°F	4 inches	144°F
8 inches	81°F	8 inches	91°F	8 inches	113°F	8 inches	131°F
12 inches	73°F	12 inches	81°F	12 inches	90°F	12 inches	126°F

To make this chart I used a laser thermometer and the average temperature of the room was 75°Farenheit (24°Celsius), so you might get slightly different results depending on the temperature of your room, but unless the difference is massive the temperature of the basking area should be similar.

As for the bulbs, I’ve been using these bulbs for a few years, but from my experience, all heat bulbs are very similar, so you can use whichever you like the most. But, make sure to avoid mercury vapor bulbs, I will explain shortly why,

Now that you know what temperature to expect from a heat bulb, based on distance and wattage, it’s time to see what temperature you actually need.

Overall most turtles require a similar temperature range, but if you want to get into detail, they are slightly different. And here is a list of the most common pet turtles and their ideal basking area temperatures:

Turtle Species	Temperature Fahrenheit	Temperature Celsius
Red Eared Slider	90 – 95°F	32 – 35°C
Juvenile Red Eared Slider	95 – 100°F	29 – 37°C
Box Turtle	80 – 90°F	26 – 32°C
Juvenile Box Turtle	90 – 95°F	32 – 35°C
Map Turtle	75 – 80°F	24 – 26°C
Juvenile Map Turtle	80 – 90°F	26 – 32°C
Mud Turtle	90 – 95°F	32 – 35°C
Juvenile Mud Turtle	90 – 100°F	32 – 37°C
Musk Turtle	85 – 90°F	29 – 32°C
Juvenile Musk Turtle	90 – 100°F	32 – 37°C
Snapping Turtle	90 – 95°F	32 – 35°C
Juvenile Snapping Turtle	95 – 100°F	29 – 37°C
Pond Turtle	85 – 95°F	29 – 35°C
Juvenile Pond Turtle	90 – 100°F	32 – 37°C
Cooter	80 – 85°F	26 – 29°C
Juvenile Cooter	90 – 100°F	32 – 37°C

As you can see juvenile turtles, which means younger turtles that can’t be classified as adults, will require a temperature that is slightly higher than that of an adult, but overall the difference is not that significant.

At this point, you are probably wondering, isn’t there a bulb that produces both UVB light and heat? Do I really need to have two bulbs, why can’t there be only one that does both things? And the answer is yes, there is a bulb that can do both things, but in my opinion, you should avoid it.

Bulbs That You Should Avoid

The bulb that produces both UVB light and heat is called a mercury vapor bulb, and while on paper it sounds like a great way to replace the two bulbs, it has one major flaw, it tends to explode.

Over the years there have been a lot of cases of exploding mercury vapor bulbs, and most of them happened out of a sudden.

So, overall I would recommend you to stay away from them. While not all mercury vapor bulbs will explode, I still don’t believe that the risk is worth it.

Can I Use a Regular Light Bulb for My Turtle?

Regular light bulbs don’t produce as much heat as heat bulbs and don’t produce UVB light, so no they can’t be used as a replacement for any basking area bulb.

But, regular light bulbs do produce some heat, and if you were to get one that is powerful enough, you could replace the heat bulb, but that regular light bulb will most likely be more expensive, consume more power, and produce a light that is way too powerful. So while technically speaking you can replace a heat bulb with a regular light bulb, it’s not practical at all.

How Long Should the Turtle Basking Light Be On?

Ideally, you want to keep the basking lights on for as long as the sun is up, so between 10 and 14 hours.

During the winter there is not as much light outside, as there is during the summer, but you should still keep the basking area on for 10 to 14 hours.

Turning the basking area on and off every day can get quite monotonous, and sometimes you can even forget. If this happens very rarely it’s not a problem, your turtle will be fine, so there is no need to spend the whole day worrying about your turtle. But let me tell you about a trick that I learned that will help you automate the whole process.

For the past few years, I’ve been using a timed outlet. This is an essential product that every turtle owner should own. The timer will automatically turn the lights on and off at certain time periods that you will set. This way you will never have to worry about forgetting to turn the lights on for your turtle when you are leaving for work or school, this will make the whole process automatic. If you could purchase just one thing that could take care of the light and temperature of your turtle’s basking area, this would be it.

Here is a link to Amazon where you can check the pricing: US Plug Format, EU Plug Format.

Final Thoughts

And that’s all there is to know about heat bulbs, UVB bulbs, and basking in general.

The wattage of the bulb is not that important on its own. What’s important is the distance at which you will place the bulb, only after you know that you can take into consideration what wattage you need.

And if you don’t already have a fixture for your bulbs, here is a link to the Lamp Fixture, that I’m using. Overall it’s a very simple fixture, that has room for two bulbs, one heat bulb, and one UVB bulb, and it can hold bulbs that are as powerful as 100W in each socket.

I will close this article with a few common questions related to this subject. But if there is anything else that you want to know, and couldn’t find in this article, you can always leave a question in the comment section down below, and I will answer it as soon as possible.

Common Questions

Do turtles need a heat lamp at night? No, turtles won’t go basking during the night, so there is no need to leave them on during the night.

Do tortoises need a heat lamp? Yes, tortoises are still turtles and most of them need to bask, so they will need a heat lamp to do so.

Will something bad happen to my turtle if I forget to turn the lamps on? If you forget for only one day, your turtle should be fine as long as you don’t do this again. Turtles can resist without light for some time, but if you forget to turn the lamps on repeatedly, your turtle will start having health problems.

Why do turtles need lamps for light and heating? In the wild, turtles get all the light and heat they need from the sun. If you keep your pet turtle indoors, you will have to provide a replacement for the light and heat that it would normally get from the sun