Optimal Water Temperature for Red Eared Sliders A Quick Guide

Perfect Water Temps for Red Eared Sliders: Quick Guide

Red-eared sliders are popular among aquarists due to their unique appearance and adaptive nature. However, setting up a proper turtle tank is not an easy task. One of the considerable things while setting up the tank for the red-eared slider is water temperature. After all, correct water temperature is vital for the well-being and health of your pet.

The right water temperature for the red-eared slider in the tank ranges between 75°F to 85°F (24-29°C). It’s crucial for their health and digestion. If the water temperature is too cold, the red-eared slider will become inactive. On the flip side, if the water temperature is too hot, the risk of shedding will increase in your turtle.

Do you know you can use a reliable aquarium heater to regulate the temperature? There are many other ways to keep the temperature suitable for the red-eared sliders. In this guide, I’ll cover everything about the too-hot and too-cold water temperature for your red-eared slider turtles.

So, let’s explore the facts!

Red-Eared Slider Water Temperature: What You Need To Know

For keeping red-eared sliders happily in the tank, maintaining an appropriate water temperature is vital for their well-being. So, aim for a range of 75-85°F (water temperature in Celsius is 24°C to 29°C) in their water tank. Otherwise, too much cold water will make them less responsive, and too much hot water will make them bacteria infectious.

So, your target as a responsible turtle keeper must be to provide an appropriate water temperature to keep the red-eared slider active and healthy. That’s why optimal temperature settings are important for your turtle’s activity and appetite. Slightly cooler or warmer water temperatures can disturb your red-eared slider.

Your favorite slider can also affect its feeding habits negatively. Interestingly, hatchlings of red-eared sliders are highly vulnerable to too-cold temperatures, especially those that are only six months old. Their possibility of getting sick and even dying due to freezing water temperature is higher than adults and older ones.

Always keep the following temperatures on your checklist:

  • Air Temperature: mid 70’s – 80’s
  • Basking Temperature:  High 80’s to low 90’s
  • Water Temperature: ~ 72 to 76 degrees for sub-adults & adults, 78 to 80 degrees for hatchlings & smaller juveniles.

Ectothermic Nature of Red-Eared Sliders

Do you have any idea that red-eared sliders are scientifically known as “ectothermic” creatures? This means they rely on external sources, like the environment, to regulate their body temperature. If the water temperature falls below the recommended range, it can pose health concerns for your pet slider.

Lower temperatures can cause your pet slider’s metabolism to slow down. This may result in reduced appetite, sluggish behavior, and an increased risk of respiratory infections. Similarly, setting temperatures too high is very harmful.

You will risk your pets’ health due to overheating in your red-eared sliders’ bodies. However, I have a fantastic suggestion for you – try using an aquarium thermometer. It’ll monitor the water temperatures accurately at the enclosure of the aquarium of your slider.

Important Note:

As the metabolism rate in baby red-eared sliders is relatively higher than in adults, they require slightly warmer water. So, 78°F to 85°F is the accurate water temperature for baby red-eared sliders. They grow properly and develop far better in a higher water temperature.

What Temperature Is Too Cold For Red-Eared Sliders?

Red Eared Sliders

According to various studies and research analyses, something that is between 65°F and 70°F is too cold for red-eared slider temperature. Hence, your slider can endure the current water temperature, but subjecting it to prolonged exposure can potentially result in organ failure. Thus, this cold temperature can pose a serious threat to your slider’s well-being!

Do you know what’s the worst cold water temperature for your cute and cuddly red-eared sliders? The temperature range of 50 to 65 degrees Fahrenheit is particularly unfavorable for your red-eared slider. It’s guaranteed that this temperature range can cause significant stress to your turtle. 

Furthermore, in a cold environment without a refuge(such as a basking spot), your red-eared slider is at risk. Without a warm escape, it may suffer a shock to its system. So, providing a suitable basking area is crucial for your turtle’s well-being.

Simply put, your slider finds temperatures below 50 degrees F (10 degrees Celsius) intolerable. Here is a video showing the behavior of a red-eared slider turtle when it’s exposed to chilly water on a cold December morning. Watch out here: Source.

What Temperature Is Too Hot For Red-Eared Sliders?

If the water temperature exceeds 90 degrees, it’s too hot for your red-eared slider. In such heat, your pet might choose to stay in the water instead of basking. However, this isn’t good! Wondering why?

This is because skipping basking time can lead to fungal infections and other health issues for your turtle. That’s why keeping the water at a suitable temperature is essential for your pet’s well-being.

Do Red-Eared Sliders Need Heated Water?

Absolutely Yes! Red-eared sliders do need heated water because it keeps their body temperature moderate. Moreover, their body metabolism rate also gets better. Usually, animal lovers living in areas where their water temperatures are very low face difficulties in keeping pets like red-eared sliders.

My suggestion for them is to purchase a red-eared slider water heater. I just like how it works and keeps the water temperature at our recommended level. Thus, you’ll keep comfortable and happy sliders.

Fun Fact!

According to various empirical and scientific data research, the exact water temperature for red-eared sliders varies a bit. It’s because it is dependent on the life stage or the size of your turtle. For example, take the following temperatures into account, but there is no exact and accurate water temperature for these stages of turtles.

  • Water temperature for hatchlings (<1 year old) — 78-82°F (24-29°C)
  • Water temperature for juveniles — 74-76°F (23-24°C)
  • Water temperature for adults — 70-88°F (21-31°C)

Do Red-Eared Sliders Need Heat At Night?

It’s a big yes. Red-eared sliders do need heat at night. It’s natural for them to experience a drop in temperature during the night, simulating their natural environment. Thus, consistency in moderate water temperature is very important for keeping the red-eared sliders safe and sound at night.

Otherwise, they will get stressed due to fluctuating water temperature. So, providing a consistent day-night temperature cycle helps maintain the overall well-being of your red-eared slider. The more you care about the water temperature, the more happily the red-eared sliders will live.

Can Red-Eared Sliders Survive In Cold Water?

Yes, red-eared sliders can survive in cold water, but not too long. Extremely low temperatures like 50 °F are unbearable for these types of turtles. Their blood circulation slows down in cold water.

As a result, their energy reserves are depleted due to continuous swimming in cold water. Then, the sliders sink into the water’s bottom. Unfortunately, they become too weak and unable to get back on the floor. In the end, they drown.

A Somber ending!


How do I keep my red-eared slider tank warm?

In order to keep your red-eared slider tank warm, try using a substrate heating pad or submersible water heater. Plus, use a reliable thermometer to check the water temperature and to keep it within the recommended water temperature range.

What is the correct water temperature for sick red-eared sliders?

Sick sliders are more vulnerable to cold water temperatures (the same case with baby red-eared sliders). You should provide them with a slightly warmer temperature. In this way, they recover quickly from the diseases that are harming their health.

How Long Can Red-Eared Sliders Live In Cold Water?

Survival of red-eared sliders in cold water varies, but it’s best to avoid extended exposure. These turtles thrive in warmer conditions, and keeping them in cold water for more than a few hours can be fatal.

However, if the red-eared slider is wild, it can survive because wild red-eared sliders can go to a brumation stage in extreme temperatures. On the other side, captive sliders get badly affected in cold water.

Do red-eared sliders need sunlight?

Yes, red-eared sliders do need sunlight. In fact, sunlight is known as their best friend. If you have ever seen them in the wild, they would definitely be basking in the sunlight.

You know red-eared sliders get vitamin D from the sunlight, which also wards off parasites from their shells. Moreover, their body temperature becomes balanced in the daylight.

Read also: Turtles’ Final Moments: Do They Pass With Eyes Open?


So, the ideal “red-eared slider water temperature” ranges from 75 to 85 degrees Fahrenheit. If you provide them with this temperature, it’s like a sweet pot for them. You can easily optimize the water temperature with the help of a few instruments mentioned above. Thus, housing red-eared sliders in their favorable environment is not a difficult task anymore. Lastly, give them a proper diet, handle them carefully, check their behavior, and visit a veterinarian if you notice any change.

I hope you enjoyed reading about how to care for your pet red-eared sliders in captivity. If you have any questions, let me know in the comments section. I’m all ears!

Sincere thanks for reading my guide. Stay tuned for reading more about these reptiles!