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8 Great Tank Mates for Red-Eared Slider Turtles (Compatibility Guide 2023)

Brooke Billingsley

By Brooke Billingsley

red eared slider on dead branch

Red-eared sliders can be fantastic pets, but their needs are specific and complex. One of the most difficult aspects of keeping these turtles is finding appropriate tank mates for them. Turtles aren’t the best tank mates between their heavy bioload and habit of consuming their tank mates, so giving your red-eared slider tank mates may be difficult to do, but it isn’t impossible.

Keep reading for some of the options for tank mates for your red-eared slider.

The 8 Great Tank Mates for Red-Eared Slider Turtles

1. Striped Raphael Catfish

Striped Raphael catfish in the tank
Image Credit: chonlasub woravichan, Shutterstock
Size 6–9.5 inches (15.2–24 cm)
Diet Omnivore
Minimum tank size 30 gallons (113 liters)
Care Level Easy
Temperament Peaceful, curious

Striped Raphael catfish are fascinating catfish that exhibit inquisitive but peaceful tendencies. They are opportunistic omnivores, so they are known for eating smaller tank mates. They usually reach around 6 inches (15.2 cm) in length, but they can exceed 9 inches (23 cm). They have small spines all over the body and the pectoral and dorsal fins have sharp, serrated spines. These fish are hard to eat because of this, making them a good tank mate for a red-eared slider. Keep in mind that turtles can choke if they attempt to eat one of these fish and it becomes lodged in its throat because of the spines.

2. Common Plecostomus – Best for Large Environments

Common Pleco
Image Credit: slowmotiongli, Shutterstock
Size 12–24 inches (31–61 cm)
Diet Omnivore
Minimum tank size 75 gallons (284 liters)
Care Level Easy
Temperament Peaceful (juvenile), semi-aggressive (adult)

The common Plecostomus is a fish that is commonly sold to unsuspecting people who aren’t aware of the large size these fish can achieve. If you have a temperature-controlled pond or a tank of at least 150 gallons, an adult common Pleco can happily live with a red-eared slider. These fish are primarily herbivorous, but they will eat meaty foods as a treat. They are known to be peaceful as juveniles but may become territorial and semi-aggressive as they age. Their armored bodies make them a poor choice for a turtle’s snack.

3. Pictus Catfish

Image Credit: Marcelo Saaver=dra, Shutterstock
Size 3–6 inches (7.6–15.2 cm)
Diet Omnivore
Minimum tank size 50 gallons (189 liters)
Care Level Easy
Temperament Peaceful

The Pictus catfish is a small catfish that stays small enough that it may be eaten by a larger turtle, but they spend most of their time staying at the bottom of the tank scavenging for food, so they’re typically out of the turtle’s way. They’re cute and active, making them fun to watch. Their peaceful temperament makes them a good option as well, but you do need at least a 50-gallon (189 liters) tank to keep them comfortable.

4. Koi Fish

koi fish in aquarium
Image Credit: TigerStocks, Shutterstock
Size 20–52 inches (50.8–132.1 cm)
Diet Omnivore
Minimum tank size 50 gallons (189 liters)
Care Level Medium
Temperament Peaceful, potentially territorial

When it comes to Koi fish, it’s important to understand that these are not aquarium fish. They are pond fish that require a minimum of 50 gallons (189 liters) of water, although 150 gallons or more is recommended. The water should be 2–3 feet (61–91.4 cm) deep as well. They are good pond mates to red-eared sliders, although turtles have been known to nip at Koi fish fins. Koi may become territorial or nippy during feeding or breeding times.

5. Mystery Snails

Mystery snail
Image Credit: Michael Strobel, Pixabay
Size 1–2 inches (2.5–5.1 cm)
Diet Omnivore
Minimum tank size 5 gallons (19 liters)
Care Level Easy
Temperament Peaceful

Mystery snails are fun and interesting snails that are active and at times seem curious and playful. They are great for cleaning up leftover food, although they should not be relied on for algae consumption. Due to their size, mystery snails may fall prey to larger red-eared sliders. Adult mystery snails are often large enough to not be eaten by juvenile turtles, though. They’re easy to care for are a surprisingly lively addition to a tank.

6. Goldfish

Carassius auratus Goldfish_gunungkawi_shutterstock
Image credit: gunungkawi, Shutterstock
Size 2–14 inches (5.1–36 cm)
Diet Omnivore
Minimum tank size 10 gallons (38 liters)
Care Level Easy
Temperament Peaceful

Goldfish can get quite large, so they aren’t always at risk of being eaten by a turtle. Many people like goldfish for turtle tanks because they’re inexpensive and readily available, so it isn’t a large monetary loss if some fish to end up being eaten. They are generally peaceful fish that can swim quickly, allowing them a good shot at dodging turtle attacks. It’s not advisable to put fancy goldfish in a turtle tank, though, because they tend to be slower and more delicate than slim-bodied goldfish.

7. Rosy-Red Minnows

Size 2–4 inches (5.1–10.2 cm)
Diet Omnivore
Minimum tank size 10 gallons (38 liters)
Care Level Easy
Temperament Peaceful, semi-aggressive (males)

Rosy-red minnows are cute, petite fish that are often sold as feeder fish. This means that, like goldfish, they are generally inexpensive and easy to come by. They reproduce quickly, so it is possible that you’ll be able to keep a breeding population of them in your red-eared slider’s tank. They are overall very peaceful, but males become aggressively protective of their eggs after spawning. Once the eggs hatch, though, the fry are on their own.

8. Guppies

Image Credit: Piqsels
Size 0.5–2.5 inches (1.3–6.4 cm)
Diet Omnivore
Minimum tank size 5 gallons (19 liters)
Care Level Easy
Temperament Peaceful, social

Guppies are low-maintenance fish that reproduce at an exceptionally rapid rate. If you keep male and female guppies together, you’ll have fry in no time. It’s almost impossible for all of the adults and offspring to be eaten before more fry are born. This can make guppies overwhelming, though, since they can overtake a tank within only a few months. They are fast swimmers and are generally likely to stay out of your turtle’s grasp, but you should expect to at least lose a few to your turtle regularly.

What Makes a Good Tank Mate for Red-Eared Slider Turtles?

The most difficult part of choosing tank mates for red-eared sliders is that they are known for eating fish, invertebrates, and other small tank mates. Ideal tank mates should either be too large to be eaten or too fast to be at too much risk. The exception to this is snails, which may not catch the eye of your turtle due to their movements being slower and smoother than most fish. Some crustaceans may succeed in a red-eared slider tank, but they are at a high risk of being eaten.

red eared slider
Image Credit: Dieter Seibel, Pixabay

Where Do Red-Eared Slider Turtles Prefer to Live in the Aquarium?

There doesn’t seem to be one part of the tank in particular that these turtles like to spend time in. They can be spotted actively swimming around at all levels, sleeping on the bottom or floating at the top of the water, or spending time out of the water in basking areas. They can’t spend long periods of time underwater and prefer shallow, slow-moving water.

Water Parameters

In their natural environment, these turtles are native to large swaths of the United States, as far north as Ohio and as far south as the northernmost parts of Mexico. They’re found as far west as New Mexico and as far east as the states that border the Atlantic Ocean. They are primarily warm-water turtles, preferring slow-moving rivers and streams. They need water temperature between 75–85°F (24–29°C) and a basking area between 85–95°F (29–35°C). Water should be well filtered to prevent buildup of ammonia and nitrite.


Hatchling red-eared sliders are usually around 1 inch in size. However, in the United States, it has been illegal since 1975 to sell turtles with a shell size smaller than 4 inches. At full adult size, they are usually between 5–9 inches (12.7–23 cm), but they have been known to reach 12 inches (31 cm).

red eared slider
Image Credit: Tanya_Terekhina, Shutterstock

Aggressive Behaviors

Red-eared sliders are usually peaceful and gentle, but they are prone to biting if startled or scared. They also have sharp claws that they can use intentionally or accidentally if scared or trying to escape. They may become territorial and have been known to nip at the fins of fish. They are usually peaceful with other varieties of turtles of a similar size, but larger red-eared sliders may hurt or even eat smaller turtles.

3 Benefits of Having Tank Mates for Red-Eared Slider Turtles in Your Aquarium

  • Cleanup Crew: Turtles are messy and they aren’t likely to clean up behind themselves. Tank mates like snails can help to keep the tank clean by eating leftover food, plant matter, and sometimes even waste.
  • Stimulating Instincts: Adding small fish, like guppies and minnows, to your turtle tank can help to stimulate your turtle’s natural hunting instincts. It can be enriching and fun for your turtle to hunt fish, but they shouldn’t be offered as a primary source of nutrition.
  • Natural Environment: Between driftwood, plants, and your turtle, your tank should already have a natural appearance. The addition of fish, especially fish native to the same areas as your red-eared slider, can really bring a more natural feel to your turtle’s home.
red eared slider in aquarium
Image Credit: Piqsels

What’s the Most Common Mistake People Make with Red-Eared Sliders?

Red-eared sliders can be wonderful pets, but they are challenging pets. They are often sold as beginner pets, but their tank setup and maintenance, temperature needs, dietary needs, and desire to be handled as little as possible can make them not a good option for beginners, especially children. The most common mistake people make with these turtles is bringing them home unprepared and not fully understanding their extensive needs. Choosing tank mates for your turtle should come secondary to ensuring your turtle’s needs are already met.

Final Thoughts

Choosing tank mates for your red-eared slider tank isn’t going to be the easiest thing. You’ll have to understand that any tank mate you add is added at your own risk. Any tank mate that your turtle thinks can fit in its mouth is at risk of being killed or hurt by your turtle. There are some options, though, and the larger the tank or pond, the more options you have. Keeping fish with your turtle is more likely to be successful in a 100-gallon (379 liters) tank than it is in a 30-gallon (113 liters) tank, and it’s even more likely to be successful in a 1,500-gallon (5,678 liters) pond.

Featured Image Credit: Simon_g, Shutterstock

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