Can Turtles Live With Fish (In the Same Tank)?

Setting up your turtle’s habitat requires a lot of effort on your part. Once the basics have been established, a common question that arises is whether they can share the same environment as fish. 

Whilst turtles and fish can live in the same aquarium, there are certain factors that you must abide by. The tank needs to be large enough to accommodate both reptiles and you also need to ensure that the species are compatible with one another. 

In our guide below, we have addressed all of the factors that you need to consider before adding fish to an aquarium with turtles. 

The Size of the Tank

Turtles require generously sized aquariums. As a general rule, your turtle needs approximately 10 gallons of water for each inch of its shell and this applies to every turtle that is going to be kept inside the aquarium. It is worth noting that some turtles can grow quite long with certain species reaching around 10 to 12 inches.

The bigger the tank the better as this provides both reptiles with a sufficient amount of space so that they do not become territorial or confrontational. Preferably, you should opt for a tank that is at least 100 gallons.  

It is also recommended that you add a few ornaments to the aquarium. Should any confrontation occur, the fish will then be able to hide in these ornaments out of sight of the turtles. 

The Compatibility of the Species

Certain species of fish and turtles are not compatible with one another and because of this, keeping them in the same aquarium is not recommended. A turtle poses a greater threat to smaller sized fish as they will typically hunt them.

On the other hand, there are certain fish that are not compatible with turtles as their bite can be harmful to them. 

Choose your species of turtle and fish carefully. Avoid turtles that are skilled hunters, e.g red-eared sliders. Certain turtles will become less of a threat as they mature.

As for the fish, ensure that they aren’t overly territorial. In regards to the size of the fish, they shouldn’t be too small, but they also shouldn’t be too big. Though this may seem a little confusing, larger fish are going to be easier for the turtles to locate and hunt.

Ideally, they should also be quite fast because they will have a greater chance of swimming away from the turtle if needed. Guppies are an option as they are swift swimmers, however, they do produce more waste. Alternatively, you may wish to add some tetras to your tank. 

The Capabilities of the Filtration System

If you intend to add fish into the aquarium with your turtles, you must make sure that it is equipped with a filtration system that can cope with the extra waste. Canister filters are a worthy option.

Instead of sitting inside the tank, they will sit beneath it and will therefore take up less space. The majority have multi-filtration capabilities that will take care of the mechanical, biological, and chemical elements. The filter isn’t just needed to deal with the waste but any leftover bits of food too. 

Remember that an unfiltered aquarium is going to be smelly and rather toxic. Turtles typically tend to be much more hardy than fish and can cope better in dirty water, fish on the other hand cannot. In fact, toxic water can poison them. 

Care Requirements

Turtles have some special care requirements and the setup of their tank must cater to this. For example, to grow healthily, they need a UVB light, a basking area, and a heat light.

Often, owners will forget to include these things if they are going to be keeping fish too, but this can have detrimental consequences on the health of your turtle.

The temperature and pH level of the water should also be right for both reptiles inhabiting the aquarium. Ideally, when keeping both reptiles, the temperature of the water should fall within the range of 75 degrees Fahrenheit to 80 degrees Fahrenheit. As for the pH levels, a figure of 7.4 to 7.5 should suffice. 

Adding the Fish to the Aquarium

Once you are confident that the setup of the aquarium is suitable for both species, it is time to start adding the fish. You shouldn’t just put the fish straight in, instead, it is important to follow a few steps. 

Your fish will need to acclimatize and get used to their new environment. Putting them into the water without allowing them to is likely to send them into a state of shock. First, you should allow the bag that your fish came in to float on the water, then slowly add water from the tank to the bag in gradual amounts. 

We would also advise you to feed your turtles before adding the fish to the aquarium. If your turtle is hungry, it is more likely to hunt the fish as it searches for its next meal. However, if it was recently fed, it isn’t as likely to view the fish as possible prey and will instead allow your fish to swim around. 

If you are feeling a little cautious about both species sharing the same environment, you may want to spend some time analyzing the behavior of each species.

If your turtle appears as a threat to the fish from the time that it is introduced, this is a sign that they should not be in the same aquarium. If neither species seems to bother one another, then they should be able to live together peacefully. 

Final Thoughts

As you can see, turtles and fish can live in the same tank so long as certain criteria are met. The feeding habits of your turtle are going to be largely influential on the success of keeping both species together.

Certain turtle species will hunt and eat the fish. Remember to make sure that the fish aren’t aggressive towards the turtles too. If they do not get along from the offset, they will need to be separated.