How Long Should a Turtle Basking Light Be On?

Turtles are fascinating creatures that make great pets. They are low maintenance, don’t take up too much space, and can be quite entertaining to watch. However, taking care of a turtle requires some basic knowledge about their needs, including how long they should bask under a heat lamp. In this post, we’ll explore how long a turtle basking light should be on and why it’s important.

It’s recommended to leave the basking area lights on for 8 to 10 hours a day. This includes the heat bulb as well as the UVB light bulb. While basking, turtles need to regulate their body temperature as well as absorb UVB rays.

But having the basking area on the right amount of time doesn’t matter if the basking area is not set up correctly. Both the UVB bulb and the heat bulb need to be positioned at the correct distance in order to provide enough heat and UVB light.

How to Correctly Set up the Basking Lights

There are two important aspects that you have to be careful about when setting up the basking area, the wattage of the bulbs, and the distance at which you place them.

The Wattage of the Heat Bulb in the Basking Area

Here are two examples of how bulbs with different wattages will work, and how you will have to set them up.

If the bulb has 150 watts, you can place it 16 inches away from your turtle, and you will get an ideal temperature, any closer than that, and it will be too hot.
If the bulb has 50 watts, you have to place it much closer to get the same ideal temperature, at about 6 inches. Any further than that and the temperature will be too low.

So it all comes down to how much space you have at your disposal, what kind of basking area you have, and the lamp fixture. There is no such thing as a general best wattage, but there is the best wattage for each specific situation. So let’s figure out what is the best wattage for you.

How Should the Bulb Be From the Turtle

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.

Distance(50 W)	Temperature(50 W)	Distance(50 W)	Temperature(50 W)	Distance(50 W)	Temperature(50 W)	Distance(50 W)	Temperature(50 W)
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 halogen 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.

How to Choose the Best UVB Bulb for Your Turtle

When it comes to choosing UVB bulbs, things are a little more complicated due to the huge variety of wattages, in which UVB bulbs can be found. And then there is the fact that most manufacturers have a different rating system, and some of them have no instructions at all.

So, for UVB bulbs, I am going to give you the exact distance for a few bulbs that I’ve used before that come from a reputable manufacturer, 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
ReptiS u n 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.

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

Why Turtles Bask

The main reason why turtles bask is to increase their body temperature, but there are other reasons why they do this.

Another important reason why turtles bask is to have access to UVB rays. UVB light plays a vital role in the production of Vitamin D3, which is essential for the calcium in the body. Without UVB light the turtles (as well as humans and many animals) won’t be able to get the proper amount of calcium which can lead to improper bone growth, metabolic bone disease, softshell, shell rot, and many other bad things.

Another important thing that happens during basking, is that the bacteria that have gathered on the shell and skin of the turtle disappear. While in the water, bacteria end up sticking to the shell and skin of the turtle. When turtles bask, they also dry themselves up, and the bacteria that they got from the water won’t be able to survive.

What Happens if a Turtle Doesn’t Bask Enough

If a turtle isn’t able to bask enough, its body will stop functioning properly. Firstly, due to the lack of UV light they won’t be able to properly process the calcium in their body and the growing process will either slow down or stop completely.

Secondly, the bacteria on their shell and body will start to get out of control, which can lead to shell rot, or other serious health problems.

Another thing that will happen is that due to the low temperature, the immunity system will slowly start to fail, which will lead to multiple health problems.

In the wild, when the winter comes and the temperature drops, turtles aren’t able to heat themselves up, so they hibernate. During hibernation, they simply sleep and wait for the temperatures to rise again.

This is a natural precess that takes place every year. But this doesn’t last indefinitely, at most turtles are able to hibernate for 3 to 5 months, depending on their species, and age.

Pet turtles don’t need to hibernate, while it is a natural process, it doesn’t have any purpose except to keep the turtle alive during the cold months. And in most cases, you won’t ever see a pet turtle, that lives in a warmed house, hibernate.

But what you might see is a turtle that is preparing to hibernate. Turtles don’t simply see that the temperature has reached 32°F and decide to hibernate. When the temperature starts to slowly drop, so does the metabolism of the turtle, which means that their overall body functions and energy levels start to drop. So turtles will start to move around less, eat less food, drink less water and even use less oxygen.

The metabolic rate will continue to slow down even further at the same time as the temperature. Up until the point where the turtle will know that it’s time to hibernate. But if the temperature will start to rise, so will the metabolic rate and the turtle will become more active.

Pet turtles, while they don’t normally experience hibernating temperatures, might experience brumation, which is the name of the process I just described.

This can happen either due to the lack of a proper basking area, or due to a sudden drop in the room temperature, which will in turn affect the temperature in the basking area.

Final Thoughts

So, a turtle’s basking lights should be on for about 8 to 10 hours per day, providing a warm and comfortable spot for your turtle to rest and bask. However, it’s important to monitor the temperature of the enclosure and adjust the bulbs accordingly to ensure that your turtle is healthy and happy.

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, my colleagues and I regularly check the comment section and answer all the questions that we find.

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

2 thoughts on “How Long Should a Turtle Basking Light Be On?”

Joyce Pierce says:
March 28, 2023 at 6:08 pm
What do I need to do to care for a baby yellow slider turtle
1. Turtle Owner Team says:
  October 18, 2023 at 12:46 pm
  Caring for a baby yellow-bellied slider turtle (Trachemys scripta scripta) requires attention to several key aspects. Here’s a basic care guide:
  Habitat Setup:
  Tank: A 20-30-gallon tank is sufficient for a baby slider, but you’ll need a larger one as it grows. A good rule of thumb is 10 gallons of water for every inch of shell.
  Water: Provide a clean aquatic environment with water that’s deep enough for swimming (3-4 times the turtle’s shell length). Ensure a filtration system to maintain water quality.
  Basking Area: Create a dry, warm basking area with a heat lamp or basking dock. The basking area should be around 90-95°F (32-35°C). UVB lighting is important for proper shell and overall health.
  Diet:
  Feed your baby slider a varied diet. They are omnivores and eat both animal and plant matter. Offer commercial turtle pellets as the staple of their diet. Supplement this with small portions of leafy greens (e.g., lettuce, kale, and collard greens) and occasional treats like aquatic plants, worms, crickets, and small fish.
  Feed your turtle every day when it’s young but adjust as it grows.
  Water Quality:
  Clean the tank and change the water regularly to maintain good water quality. Turtles are messy eaters and produce waste, which can quickly degrade water quality.
  Temperature:
  Maintain the appropriate temperature in the tank, as mentioned earlier. Use a good-quality aquarium heater to keep the water temperature stable.
  Hiding Spot:
  Provide a hiding spot or cave-like structure in the tank for the turtle to rest and feel secure.
  Handling:
  Be gentle when handling your baby turtle. Excessive handling can cause stress.
  Observation:
  Monitor your turtle’s health regularly. Look for signs of illness, infection, or shell problems. If you notice any concerning changes, consult a vet with experience in reptile care.
  Future Planning:
  Keep in mind that yellow-bellied sliders can grow quite large, so you’ll need a larger tank or outdoor pond as they mature.
  Remember, taking care of a turtle is a long-term commitment, as they can live for several decades. Proper care is essential for their well-being. If you have any specific questions or concerns about your baby yellow slider, feel free to ask for more guidance.