Red Eared Slider Tank Setup

One of the most common mistakes for new owners for red-eared sliders is to invest in a tank that is too small and won’t keep up with the growth of their pet. What started out as a quarter-sized hatchling can reach an adult size of 6-8 inches as a male or 8-10 inches as a female, and have been known to reach sizes of up to 12 inches.

Red Eared Slider Tank Size

For your baby/juvenile turtles, you’re going to want to start with a tank size of at least 30 gallons. This is the minimum to ensure that they have enough space to swim around and make themselves comfortable. As the turtles grow, however, you will need to upgrade, so it may be worth it to invest in a full-size tank right off the bat.

An adult red-eared slider should have a tank that is no less than 55 gallons (48” in length). A good way to calculate the space requirements on your turtle is to look at your turtle’s total body length. As a guide, you want

  • Water depth 1.5 to 2 times your turtle’s body length
  • Tank length 4-5 times your turtle’s body length
  • Tank width 2-3 times your turtle’s body length

The reason these turtles require so much space is that in addition to their needing space to swim, you will need to provide them with a land area. This gives them space to pull themselves out of the water to bask and rest, but will take up a good amount of space. Scroll down for more information on red eared slider basking areas.

Tank Mates

If you want to house more than one adult red-eared slider in the same tank, then you should be adding about 10 gallons/12 inches of length to your tank’s capacity per adult turtle. This will ensure that the turtles have enough space to stretch out on their own without getting in each other’s way.

In terms of non-turtle tank mates, sliders usually do not play well with others. Fish and other creatures are liable to get eaten, or at the least have their fins nipped. Other than fellow turtles, it isn’t advised to put other animals in the tank with your sliders.


Plants can make for a great addition to your red eared slider tank. They participate in the nitrogen cycle by removing nitrate from the water, and they also give your sliders something healthy to nibble on. Greens are actually a crucial part of a red eared slider’s diet, and aquatic tank plants mimic what they would eat in nature. For a list of slider-friendly edible plants, visit our diet and nutrition page.

Do not include plastic or other artificial plants into your red eared slider tank. Your slider will eat them, with disastrous consequences. Besides being unhealthy, torn up plastic plants can cut your turtle internally or cause digestive blockages. If you choose to forgo natural plants, it’s best to leave the tank bare.


Unfortunately, may pet shops push gravel as a substrate for aquariums. Unless you’re raising fish with tiny mouths, gravel is always a bad idea. Red eared sliders will nibble on or eat anything they can, which means gravel-bottomed tanks invite trouble. Ingested gravel can cause internal injuries or block a slider’s digestive system, leading to death. Below is a turtle that was living in a gravel tank, along with gravel it pooped out after being removed from that tank.

Red Eared Slider Tank Setup - Bad Substrates

With that said, you have two generally accepted substrate options:

  • Bare-Bottom Tank: The easiest to clean by far. Sliders are able to move around perfectly well on the glass, and heavy waste sits there for easy removal. This is the best option if you’re going for low-maintenance.
  • Sand Bottomed Tank: Sand is small enough to pass through a slider’s digestive system if eaten. It is also aesthetically pleasing and lets your turtles leave footprints as they prance around. In terms of cleaning, waste usually sits on top and sand can be cleaned with a gravel vacuum. Sand should never be layered more than 1-2 inches, and should be stirred up weekly to make sure there is no buildup of gas or anaerobic bacteria (bacteria that grows in oxygen-free environments).

Basking Area

A turtle’s basking area is one of the most important part of your tank setup. The time that a turtle spends basking allows it to dry its shell to promote healthy growth as well as letting it suck up essential vitamins from light.

You want to make sure that you choose a basking area that doesn’t take away too much from your turtle’s swimming space, while also making sure it’s sturdy enough to support your slider’s weight. You can check out our post on choosing a turtle basking area for more info on this.

Keep Reading: Red Eared Slider Care Sheet

  1. Tank Size and Setup – Current Page
  2. Filter and Water Temperature
  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