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Many aquarium hobbyists are under the impression that fish and turtles simply can’t coexist. This is understandable considering that most turtles are aggressive hunters that enjoy a good tasty meal that consists of fish as often as possible. The thing is it’s not always about the eating habits of turtles that determine if fish and turtles can exist in the same tank. Read on and you will come to find out that certain species of fish can survive and even thrive in an aquarium that has turtles present if certain conditions are met.

It takes careful planning, getting the details right, and a little luck all at the same time. You must also keep in mind that the results are not going to be exactly the same for every aquarium owner that tries to house fish and turtles. So some adjustments and experimentation might be needed during this process also.

Reasons Why Putting Turtles and Fish Together In Aquariums Does Not Always Work

Here are some of the main reasons why most aquarium owners do not try to keep turtles and fish in them at the same time:

  • Turtles are omnivores who will pursue fish that are placed in a tank with them
  • More room is required in a tank for a turtle to move around in and the fish to have enough room to evade them (approximately enough space to hold 10 gallons of water for each 1-inch of turtle shell length)
  • A significant increase in infiltration is needed when turtles are kept in the same tank as fish
  • Snapping turtle species don’t coexist with anything
  • It’s not easy to accommodate fish tanks with such things as basking areas, UVB light, and heat lamps that turtles require for healthy growth

Determining Factors for Housing Fish and Turtles

Here are some of the factors that determine if you should keep fish and turtles in the same tank:

1. The Species of the Fish

Here are some species of aquarium fish that are known to survive quite well in tanks that also have a turtle:

  • Suckerfish varieties like Plecos grow fairly large and are generally thought to be safe from turtles that are similar or smaller in size than them. They also offer the added benefit of keeping your tank cleaner because they feed off of algae.
  • Guppies are one of the most popular aquarium fish because of their big tails and multi-colored bodies. They are also very agile and quick swimmers that are quite difficult for turtles to get a bead on and catch.
  • Pictus Catfish (also known as Pictus Cat and Angel Cat) is a popular aquarium fish that thrive in bigger type tanks like those that people often keep turtles in. They are also very active and fast fish that turtles have trouble catching and eating.
  • Neon Tetras are another aquarium fish variety that is known to be lightning-quick swimmers that are hard for turtles to catch. They look great but are known to destroy aquarium plants if not kept well-fed.
  • Peppie species of fish such as Rosy Barbs are known to do very well when living alongside turtles. They are highly decorative aquarium fish that are easy to take care of too.
  • Comet goldfish and Shubunkin goldfish are thought to be the best choices of goldfish to place in a tank with a turtle because of their quickness.

2. The Species of Turtle

Here are some turtle species that aquarium owners have had success with when it comes to keeping them from eating all of the fish in a tank:

  • Pink Belly Sideneck Turtles are a favorite of turtle enthusiasts and can cohabitate with aquarium fish if it’s done the right way when they are smaller.
  • Painted turtles are also another aquarium favorite that is ideal to pair with fish in an aquarium because they are only known to prey on very small varieties of fish.
  • Red Eared Sliders are best added to a fish tank when they are older because as they age they become less interested in protein and more interested in greens and other aquatic plant food.
  • Mud and musk turtles seem to be somewhat disinterested in hunting and are generally not very good at it when trying to do it.

As was mentioned, you never want to keep any variety of snapping turtles in a tank that you also keep fish in.

3. The Cost of Your Fish

There are times it’s just not worth the risk to pair up turtles and fish in an aquarium. An example of this is if you have very expensive tropical fish. It’s just not worth putting a turtle and the tank and losing your investment. Even if your prize tropical fish do survive chances are they will at least get part of their fins eaten and not look as good. This is the reason that many people put goldfish and minnows in tanks with turtles they are inexpensive and it’s not hard to replace them if they get eaten.

4. Some Fish Can Be a Threat to Your Turtles Safety

Sometimes this aggressive fish hunter becomes the hunted in an aquarium setting. It’s not always the case where the turtle is the aggressor in a fish tank. If you have big enough or voracious enough fish, they may actually be a threat to the turtle you have placed in your fish tank. This is true of much bigger aquarium fish such as Koi. Oscars are another example of a tough and aggressive fish that is known to kill and eat turtles.

Common musk turtle Sternotherus odoratus in a pond.

How to Increase the Chances of Your Fish Surviving In a Tank That Has a Turtle?

Here are some ways to help keep your fish alive when housing them in an aquarium with a turtle:

1. Keep Your Turtle Well-Fed

Turtles are not like humans and just eat for enjoyment. That means that your fish have a better chance of survival in an aquarium with them if your turtle is well-fed. Turtle pellets or other food sources such as crickets, mealworms, and leafy vegetables will keep your turtle full and disinterested in making a meal out of the fish in the tank or pond with it.

Provide Secure Places for Your Fish to Hide

Many varieties of aquarium fish are quick and nimble and given a place to hide can keep from getting easily eaten by a turtle that shares their aquarium tank. Here are some great ways to provide your fish with hiding spots that can keep them safe from turtles:

  • Lay PVC pipe in the tank with small holes drilled in it that are only big enough for the fish to get into
  • Purchase specially made aquarium buildings and structures from your local fish supply store
  • Clay flower pots with holes in them turned upside down make excellent places for aquarium fish to hide from turtles
  • Place larger size rocks at the bottom of the aquarium close enough together so only the fish can swim between them
  • Driftwood pieces with irregularly shaped edges make good places for fish to hide from the turtles they share an aquarium tank with

Keep in mind that just relying on aquarium plants and other tank vegetation to keep your fish from getting eaten by your turtle is not a good idea. Turtles are big and strong enough to just bulldoze through this type of fish tank bottom structure.

2. Do Not Ever Feed Your Turtle Feeder Fish

Most people have heard stories about how lions and tigers, once they get a taste for human flesh, will become more dangerous because they will then start to seek it out. Turtles act much the same way when it comes to eating fish. If you give them feeder fish it will become an acquired taste and they will become more aggressive towards the fish in your tank.

3. Experiment with Compatibility before Populating Your Fish Tank

If you want to keep a turtle in the same aquarium that you keep your tropical fish in, then don’t just go out and buy a large amount of fish to populate your tank. Experiment first by adding just one or two fish of a few different species at first to test for compatibility with your turtle. This will give you a great idea of how to further populate your aquarium with fish varieties that will survive alongside your turtle.

4. Condition a Young Turtle to Not Hunt Fish

Some new aquarium owners who wish to have a turtle in their fish tank have had success starting out with young turtles. They add them to the tank several months before they introduce fish into the aquarium tank. This is thought to condition the young turtle not to see the fish that are subsequently placed in the aquarium as a potential food source. Turtles are also known to be less aggressive fish hunters as they mature.


Hi, my name is Jordan. I've been in the fishkeeping hobby since my childhood. Welcome to my blog where I help fishkeepers enjoy the hobby by offering free guides, advice, & product reviews. Read more...