Red Eared Slider Water Temperature and Filter


Choosing a good filter for your Red Eared Slider’s tank is one of the most crucial parts of tank setup. The reason for this is that turtles produce a LOT of waste. This waste has a lot of toxic ammonia in it, and even in a properly cycled tank you’ll need a good filter to keep up with what your turtles are dumping in the water. A common mistake for new turtle owners is to get an underpowered filter, leaving them with filthy water and unhappy pets.

Because of this, it is important that you get the largest and best filter that you can. Any filter you settle on should be sized for a tank at least double the size of the one you put it in (ex: for a 60 gallon tank you’re going to want a filter rated for a 120 gallon tank).

For a detailed breakdown on what to look for, check out our post on red eared slider tank filters.


Water Temperature

NOTE: This section refers to water temperature requirements only. For required temperatures in the basking/above-water area, visit Red Eared Slider Lighting Requirements.

Good temperature regulation in your slider’s habitat is essential to its health. Turtles are ectothermic animals, meaning that they rely on external heat sources as their body cannot self-regulate its temperature. As a result, sustained low water temperatures of 65-72F/18.3-22.2C or lower can lead to health problems or even death for your cold-blooded pet.

One of your first investments should be an aquarium thermometer so you can keep track of your water temperature and know if it’s running too high or two low. For recommended temperature ranges, see below:

  • Young or Sick Read Eared Sliders
    • In the case of young sliders or sick turtles, it is best the keep the water temperatures a few degrees higher than you do for healthy adults (78-82°F/25.5-28°C). This keeps their metabolisms going at a healthy pace so they can grow or recover from their illness more easily.
  • Adult Red Eared Sliders
    • A healthy adult red-eared slider requires a maintained water temperature of 75-78°F/24-25.5°C in order to stay active and maintain a healthy metabolism. At lower temperatures their metabolism will slow and they will not eat, and if the temperature is too high you run the risk of cooking your pet. One of the best first investments you can make as a turtle owner is in a good aquarium thermometer to monitor your water temperature.
Temperature Maintenance

If you have a house where the temperature of the room the turtle’s tank is in is constantly at or exceeding 75F/29C then you should be fine. If this is not the case, then you may want to consider investing in a water heater for your turtle tank. A water heater allows you to pre-set a temperature to keep the water at so you don’t have to worry about temperatures falling too low in cooler homes or in winter. It is important to not that sunlight, a basking light, or a heating pad is NOT an effective way to heat water, and risks temperatures running either too low or too high.

Most turtle owners use turtle tank heaters to keep their tanks warm. There are two main types used by turtle owners: submersible types which are essentially a heated rod you put in your tank for direct water heating, and in-line types which connect to a filter to heat water before it’s returned to the tank. If you want to learn more about the types of heaters and options available, refer to our post on turtle tank heaters.



Keep Reading: Red Eared Slider Care Sheet

  1. Tank Size and Setup
  2. Filter and Water Temperature – Current Page
  3. Lighting/Heat Requirements
  4. The Nitrogen Cycle
  5. Tank Cleaning and Water Chemistry
  6. Diet and Nutrition
  7. Illnesses and Injury
  8. Additional Reading and Resources