Can You Put Turtles in a Fish Tank? (And what size required)

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by Jason Matthews



Setting up the right habitat for your turtle will require some planning, effort, and time but the result will be a happy and comfortable turtle. Many turtle owners want to know if they can put turtles in a fish tank or do they need something else to live in. 

Turtles can live in a fish tank. When living in an apartment, placing your pet turtle in a fish tank along with your pet fish is more convenient. Most turtle species can live with fish without a problem, or you can keep the turtle alone, creating the perfect terrarium.

When you want to put turtles in a fish tank with your pet fish, there are a few things that you need to consider besides compatibility with the fish. Make sure you have a fish tank that is big enough to house the turtle and the fish, you maintain the perfect aquarium conditions for all the species, and you have a good filtration system that can easily filter and clean the water without a problem. 

Putting the Right Fish Species with Turtles

Many turtle species are more than willing to swim and chase fish until they can capture and eat them. Hence, you do not want to place your pet turtle in a fish tank that contains small and slow-swimming fish species. If you do this, the turtle will view the fish as prey, and before you know it, the turtle will devour them. Hence, choose fish species compatible with the turtle and can survive. 

Usually, it is advisable to select fish species that are not too small and can swim fast. The fish can swim fast and stay clear of the turtle. Also, you should ensure that the fish tank is big enough for you to provide hiding spots for the fish. Fish tank decoration, hollow PVC pipes, and dense aquatic plants are some of the things that you can introduce in your fish tank for fish to avoid your turtle. 

Avoid goldfish if you want to keep fish and turtles together in a fish tank. While this fish is large, it is a slow swimmer. Hence, the turtle will feast on it without a problem.

Some of the fish species that are compatible with turtles include:

Why Use a Fish Tank for Turtles?

Fish tanks are available in various sizes, shapes, and types. You can choose a size that is right not just for your turtle but also for the fish that you intend to keep. While most fish tanks are rectangular, you can get tanks that are square, circular, or other shapes. 

Some of the other reasons to use a fish tank for a turtle are:

  • Fish tanks are aesthetically pleasing and can add style to a room
  • They are sturdily built and are reliable
  • Fish tanks are easier to set up compared to creating a turtle habitat in a pond or tub
  • The filters and water heaters that are available on the market are usually designed and built for fish tanks, and hence, they work more efficiently when used with an aquarium
  • Fish tanks are easy to procure – you will find tanks in pet stores, supermarkets, and in online stores
  • Fish tanks are easy to decorate with the right aquascape for your pet turtle and fish
  • These tanks are also easy to clean, and thanks to the see-through glass, you will be able to monitor and see the animals without a problem

Disadvantages of Using a Fish Tank for a Turtle

While there are several advantages of using a fish tank to put a turtle, you should also be aware of the drawback to make an informed choice. 

The biggest disadvantage of using a fish tank to put your turtle in is the size. You would have to invest in a huge tank. Generally, you need 10 gallons of water for every 1 inch of the turtle’s shell. Imagine getting a red-eared slider – this turtle species can grow quite big, with females growing to around 12 inches. So, if you have a female red-eared slider, you need a 125-gallon fish tank. 

Many people make the mistake of buying a small fish tank when they get a juvenile turtle. However, with the right care and diet, a turtle can grow big quite quickly; before they know it, the tank is too small. So, they have to spend money on buying a bigger tank, which can be quite expensive. 

Choosing the Right Fish Tank Size

If you intend to keep your pet turtle in a fish tank without fish, follow the rule – 10 gallons for every 1-inch of the shell. On the other hand, if you want to keep a turtle and fish together, you must be a little more careful about choosing the right fish tank size. 

If the tank is too small, the filter will not be able to work efficiently. This will compromise the water and living conditions, lead to bacteria proliferation, and cause algae and fungi to grow in the tank. 

Here are some numbers that you should remember when buying a fish tank for your turtle and fish:

  • 30-gallon fish tank for turtles up to 6 inches
  • 55-gallon fish tank for turtles 6 to 8 inches
  • A minimum of 75 gallons for turtles that are more than 8 inches

When you house a turtle with fish, do not think of loading the fish tank with an entire school of fish. Instead, look to have less than 10 fish in the tank. Furthermore, ensure that the water is deep enough for the fish and the turtle to swim without being cramped. Experts state that if you have a turtle in a fish tank, the water should be twice as deep as the turtle. For instance, if your turtle is 6 inches long, the water should be at least 12 inches deep

Besides water, the turtle also needs a basking area. So, ensure that you place a basking dock for the turtle so that it can leave the water and enjoy its time under the light. 

Fish Tank Conditions

  • Temperature and pH: When you want to house turtles with or without fish, ensure that the temperature of the water is around 76 deg F and the pH of the water is 7.5. Not only will the turtle be happy but also the fish.
  • Filter System: When you have a turtle and fish together in a fish tank, there will be a lot of waste generation. So, choose a canister filter instead of going in for a submersible filter. Such a filter will be powerful enough to clean the water, and since it is an external filtration system, it will not take up space in the fish tank. 

The Best Turtle Species for Fish Tanks

Snapping turtles and map turtles are carnivores and hunt fish for food. So, these turtles are not suitable for fish tanks with fish. You can keep these turtles in a fish tank without the fish. 

If you have fish and want a pet turtle, go with a red-eared slider, mud turtles, painted turtles, and musk turtles. These are aquatic turtles and can cohabit with fish without a problem. 


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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