Red-Eared Slider Correct Temperatures (Beginners Guide)

Despite their rough-looking exterior, Red-Eared Sliders are very sensitive to their environment, and one of the most important aspects is the temperature of the tank. If the water is too hot or too cold it can lead to health problems, and the same thing applies to the basking area.

On average the temperature of a Red-Eared Slider tank should be between 72 and 76°F (22 to 24°C). And the temperature of the basking area should be between 85 and 95°F (29 to 35°C).

Getting the right water temperature is quite simple, all you need is a good water heater. But getting the correct temperature in the basking area is a little trickier since you have to use a heat bulb, and depending on how many watts it has and how close or far you place it you will get very different temperatures.

But before we see how to get the correct temperature in the basking area, let’s start with the simpler part, the water tank.

How to Get the Correct Temperature in the Tank

Now that we know what is the correct temperature for turtle tanks, let’s see how we can get that temperature.

To be able to control the temperature of the water in the tank you are going to need a water heater, but not any water heater will do. You need a water heater that:

• Has a heat guard – so that your turtle won’t get too close and burn itself
• Is sturdy – turtles tend to break things in their tank, so you need a heater that won’t break easily
• Adjustable temperature – not all heaters are adjustable, so make sure that you get one that is
• Has enough power – turtles need big tanks, and not all heaters are able to heat a turtle tank, as most of them are designed for smaller fish tanks

After you get a good water heater you can simply set it up and forget about it. The only times when you should check up on it is when there are significant temperature changes in the room with the tank, for example when it’s a really hot summer day or a very cold winter night. Sometimes those extreme temperatures can be too much for the heater to work and you might want to intervene manually by adding some cold or warm water to the tank.

But overall if you get a good water heater you shouldn’t have to worry about the temperature of the water.

If you want a recommendation, here is a link to the tank heater that I’ve been using for the last 5 years: Submersible Aquarium Heater. I don’t have too many things to say about it, it’s a good and reliable heater, it comes with a guard, and you can easily select the temperature, it can heat up a 100-gallon tank, so everything that you want from a heater.

How to Get the Correct Temperature in the Basking Area

In order to get the correct temperature in the basking area you will need to use a heat bulb.

Heat bulbs are similar to normal light bulbs that we use around the house, the only difference is that those bulbs create a lot more heat than a regular light bulb.

Bulbs come with different wattages, from 50 watts to 75, to 100 watts, and up to 150 watts. And each wattage is good in certain situations. I have an in-depth guide on how to choose the right heat bulb for your basking area, that you can find right here: Turtle Basking Light Wattage (Illustrated Beginners Guide). Here is an extract from that article that will cover the basics:

In short, there is no best wattage, a 50-watt bulb can be as efficient as a 150-watt bulb. It all comes down to the way your basking area is set up, more precisely, it comes down to how far away your bulb is from your turtle.

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

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.

One more thing that you should know about baking areas is that they usually have two bulbs, one to create heat, and one to generate UVB light. And both of them are just as important for the health of your turtle, so let’s take a quick look at the UVB bulbs, and how to choose the right one for your turtle.

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

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 Stay Away From

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 in the Basking Area?

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 Thought

So, the average temperature of the water in the tank should be between 72 and 77°F (22 to 25°C), and the temperature of the basking area should be between 85 and 95°F (22 to 35°C).

From my experience with red-eared sliders, I’ve learned that temperature is important, but it’s not something that you should stress yourself too much. In the wild, they don’t always get to live in water with the perfect temperature, and the basking temperature is very rarely as hot as they need.

So as long as you stay in the ranges mentioned in this article your red-eared slider will have no problem with the temperature.

I hope this article answered all your questions regarding turtles and what temperatures they need in their tank and basking area. If there is anything else that you would like to know, feel free to use the comments section below and leave your questions there, I regularly check the comment sections and answer all questions.

Hello,

If you enjoy the content that we create, please consider saying a "Thank You!" by leaving a tip.

Every little bit can help us tremendously in continuing to create quality content that helps turtle and tortoise owners around the world.

We really appreciate the kindness and support that you show us!