fish jumping out of bowl

Estimated reading time: 11 minutes

Have you ever wondered why your fish is suddenly jumping out of your aquarium? It’s more than just quirky behavior – it’s often a sign of discomfort or stress in their environment.

This article will delve into the various reasons for this potentially dangerous action and provide you with practical strategies to prevent it.

Leaping Fish – Who's Likely to Jump?

Let's dive into a fin-tastic quiz about which pet fish are more likely to make a splash by jumping out of their aquariums. Get ready to test your knowledge and maybe learn something new about our aquatic friends!

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Which of these fish is known for its high-jumping skills, often leaping out of the water?

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Which of these freshwater fish is least likely to try jumping out of an aquarium?

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What is a common reason why many fish jump out of their tanks?

4 / 4

This fish is a notorious jumper and needs a securely covered tank to prevent escape. It's also known for its aggressive nature.

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Key Takeaways

  • Fish may jump out of their tank due to factors like lack of oxygen, dirty water, incorrect temperature, stress from disease or parasites, predators in the tank, being spooked by something, looking for food, or physical obstructions.
  • To stop fish from jumping out of the tank, maintain proper water conditions by testing parameters and cleaning regularly. Provide enough hiding places with rocks, plants, PVC pipes or tubes. Keep compatible tank mates and use a secure lid or cover. Create a less stressful environment and avoid overcrowding.
  • It’s essential to ensure the safety and well-being of your fish by taking precautions against potential hazards that could cause them to jump out of their tanks.

Reasons for Fish Jumping Out of Their Tank

goldfish near surface

Lack of dissolved oxygen

Aquarium fish jump out of the tank because there is not enough oxygen in the water. If they can’t get it from the water, they try to find it somewhere else.

This makes them jump out of the tank and look for a new home with more oxygen. Too much dirt or heat in the tank water can take away this needed oxygen.

So keep your fish happy by making sure their tank has lots of clean, cool water full of air!

Dirty water

Dirty water is bad for fish. It can have lots of stuff that hurts them like ammonia and nitrites. Fish need clean water to stay healthy. They also need oxygen in the water. Dirty water doesn’t have a lot of oxygen.

Fish might try to jump out if the tank water is dirty. This may be a way for them to escape bad conditions in their home aquarium. If you see your fish trying to leap out, check how clear the tank is right away!

Incorrect water temperature

Fish get upset if the tank water is too hot or too cold. Each fish species likes a certain water temperature. If it’s wrong, they may jump out of their tank. Keeping the right water temperature is important for fish health.

Check and change the tank water often to stop this from happening. This will also lower the risk of your fish trying to escape by jumping out.

Stress from disease or parasites

Stress from disease or parasites is a major reason why fish jump out of their tanks. When fish are sick or have parasites on their skin, it can cause them a lot of stress. This stress makes them more likely to try and escape from the tank by jumping out of the water.

Parasitic infestations can be painful and harmful to fish, which can make them feel so uncomfortable that they just want to get away.

So, it’s really important for pet owners to keep an eye on their fish’s health and take steps to prevent and treat any diseases or parasites that may be causing stress.


Pet fish may also jump out of the aquarium if they feel threatened by predators. Even though our home aquariums are usually safe from large predators, some fish still have an instinct to escape when they sense danger.

This behavior is more common in certain species of fish that are known to be prey in the wild. So, if your fish jumps out of its tank, it could be because it feels like it’s being hunted or chased by another fish or creature in the tank.

Spooked by something

Fish can sometimes get spooked by sudden movements or loud noises, causing them to jump out of their tanks. This can happen if there is a lot of commotion near the tank, like people walking by or other pets running around.

Even if they are in a safe and secure tank, fish may still have natural instincts to flee when they feel threatened. It’s important for pet owners to be mindful of this and try to create a calm environment around the tank to prevent their fish from getting startled and jumping out.

Looking for food

Fish may jump out of their tanks in search of better food sources. This could happen if they are not getting enough to eat or if the food in their tank is not appetizing. In some cases, a lack of dissolved oxygen in the water can also lead to a decrease in food availability for fish.

When there is low oxygen levels, it affects the natural ecosystem within the tank and reduces the presence of small prey organisms that fish feed on. Poor water quality, such as high levels of ammonia or nitrate, can also affect the ability of fish to find and consume food.

It’s important to ensure that your fish are being fed an appropriate diet and that their tank is clean and well-maintained with good water quality.

Physical obstruction

Physical obstruction refers to any objects or barriers in the tank that can prevent fish from staying in the water. Sometimes, fish may jump out of their aquarium if there are obstacles blocking their way or if they feel trapped.

For example, decorations like rocks or plants placed too close to the surface of the water can give fish a platform to leap off. Similarly, open spaces around filter pipes or gaps in the tank lid can also provide an opportunity for escape.

It’s important to arrange the items in your tank carefully and ensure there are no openings where fish could jump out.

clownfish in tank

Preventing Fish from Jumping Out of the Tank

To prevent fish from jumping out of the tank, maintain proper water quality, provide enough hiding places, keep compatible tank mates, use a secure lid or cover, create a less stressful environment, and avoid overcrowding the tank.

Maintain proper water quality

To keep your fish safe and prevent them from jumping out of their tank, it’s important to maintain proper water quality. Here are some tips:

  1. Regularly test the water parameters like ammonia levels and pH levels to ensure they are within the appropriate range.
  2. Establish a nitrogen cycle in the tank to keep ammonia and nitrite levels low.
  3. Clean the tank regularly by removing any uneaten food, waste, and debris.
  4. Perform regular water changes to keep the water clean and fresh for your fish.
  5. Avoid overfeeding your fish as excess food can lead to poor water quality.
  6. Use a high-quality filter to remove impurities and keep the water clean.
  7. Avoid using chemicals or medications that can harm your fish or alter the water chemistry.

Provide enough hiding places

To prevent your fish from jumping out of the tank, it is important to provide enough hiding places. Hiding places can make your fish feel secure and reduce stress, decreasing the likelihood of them trying to escape. Here are some ways to provide enough hiding places for your fish:

  1. Use rocks, caves, or driftwood: These natural decorations can create hiding spots for your fish. They can swim into these areas when they feel threatened or want some privacy.
  2. Add plants: Live or artificial plants can offer shelter and cover for your fish. Plants with broad leaves or dense foliage can create a safe space for them.
  3. Include PVC pipes or tubes: These can be placed vertically or horizontally in the tank to give your fish additional hiding options. Just make sure the openings of the pipes are large enough for them to enter and exit easily.
  4. Use aquarium ornaments: Decorative items like castles, ruins, or shipwrecks often have cavities that fish can explore and hide in.
  5. Provide floating objects: Floating objects like lily pads or floating plants on the water’s surface can create a sense of security for some species of fish.
  6. Arrange the tank layout carefully: Make sure there is ample open swimming space along with hiding spots to create a more natural environment.

Keep tank mates compatible

To prevent fish from jumping out of the tank, it’s important to keep tank mates compatible. This means choosing fish species that get along well and have similar needs and temperaments.

Incompatible tank mates can lead to bullying, territorial disputes, and stress for the fish, which may cause them to try to escape. Here are some tips for keeping tank mates compatible:

  • Research before adding new fish: Before introducing a new fish species into your aquarium, make sure to research its temperament, size, and specific needs. This will help you choose fish that are more likely to coexist peacefully.
  • Consider the size of the tank: Ensure that your tank is large enough to accommodate all the fish comfortably. Overcrowding can lead to aggression and competition for resources, increasing the chances of fish jumping out.
  • Avoid mixing aggressive and peaceful species: Some species of fish are naturally more aggressive than others. Mixing aggressive species with peaceful ones can result in stress and conflicts among tank mates. It’s best to choose fish with similar temperaments.
  • Provide hiding places: Having enough hiding places in the tank can help reduce stress and provide territories for individual fish. This will give them a sense of security and minimize aggressive behaviors.
  • Observe feeding habits: Some species of fish are known to be fin-nippers or overly competitive during feeding time. Avoid keeping these types of fish together as they can cause stress and injure other tank mates.

Use a secure lid or cover

To prevent your fish from jumping out of the tank, it’s important to use a secure lid or cover. This will help keep them safely inside the aquarium and minimize any potential escapes.

Here are some options you can consider:

  1. Hood or canopy: Many aquariums come with a fitted hood or canopy that provides a secure covering for the tank. Make sure it fits snugly and has proper openings for equipment, such as lights and filters.
  2. Mesh cover: Another option is to use a mesh cover made specifically for aquariums. This allows for airflow while preventing fish from leaping out of the water. You can find mesh covers in various sizes to fit different tank dimensions.
  3. Window screen framing material: If you prefer a DIY approach, you can use window screen framing material to create a custom cover for your tank. Cut the material to match the shape and size of your aquarium, then secure it tightly using clips or adhesive.
  4. Glass or acrylic lid: Some fish tanks have glass or acrylic lids that can be placed over the top of the tank. These provide a clear view of your fish while keeping them safely contained.

Create a less stressful environment

To prevent your fish from jumping out of their tank, it’s important to create a less stressful environment for them. Here are some ways to do that:

  • Maintain good water quality: Regularly clean the tank and perform water changes to keep the water clean and free from harmful substances.
  • Provide hiding places: Add plants, rocks, or ornaments to the tank to give your fish places to hide and feel secure.
  • Choose compatible tank mates: Make sure the fish in your tank get along well and won’t stress each other out. Research different species before adding them to your tank.
  • Use a secure lid or cover: A tight-fitting lid or cover will prevent your fish from jumping out of the tank.
  • Keep the environment calm: Avoid loud noises or sudden movements near the tank as they can startle the fish and cause them to jump.
  • Don’t overcrowd the tank: An overcrowded tank can lead to aggression and stress among fish. Make sure there is plenty of space for each fish to swim comfortably.

Do not overcrowd the tank

  • Provide enough space for your fish to swim freely without feeling cramped or stressed.
  • Overcrowding can lead to territorial disputes and aggression among tank mates, increasing the risk of fish jumping out.
  • Ensure that each fish has enough territory and hiding places to establish their own territory and feel secure.
  • Research the specific needs of each fish species you plan to keep to determine the appropriate tank size and stocking levels.
  • Regularly monitor your tank’s population and remove or rehome any excess fish in the tank to prevent overcrowding.
  • A well-balanced and properly stocked tank will reduce stress levels in your fish and minimize the chances of them attempting to jump out.
fish jumping out of water


There are several reasons why fish may jump out of their tanks. These include a lack of oxygen, dirty water, incorrect water temperature, stress from disease or parasites, predators, being spooked by something, looking for food, and physical obstructions.

To prevent fish from jumping out of the tank, it is important to maintain proper water quality, provide hiding places and compatible tank mates, use a secure lid or cover on the tank, create a less stressful environment, and avoid overcrowding.

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Written by Tom Cashman

I have grown up with pets for almost fifty years. My family has strong ties to the animal shelter community in Chicago. Currently I have two cats: an orange tabby named Zelda, and a gray mixed named Zander. Like all of my pets, they were adopted from a local animal shelter. Pet Zone represents my passion for sharing with the pet community.

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Why Do Fish Jump Out of the Tank?

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