Fish

Why Do My Fish Sit at the Bottom of the Tank?

If you are an aquarist, you might probably be looking to find all your fish swirling and dancing all through the tank. But, there are times when you may notice that the fish stay at the bottom of the tank or just sitting there idly.

Ever wondered why fish sit at the bottom of the tank? If you are worried, you have a valid reason to be worried. Let us understand the reasons why your fish stays at the bottom of the tank.

Why Do Fish Lay at the Bottom of the Tank?

Finding your fish sitting at the bottom of the tank can be a very worrying and perplexing scenario. However, understanding the causes of this weird behavior can help you fix the problem, if there is any.

fish stay at the bottom

It may be noted that there are both concerning and not-so-concerning reasons as to why the fish might lay at the bottom of the tank. Let us analyze both of them so that you can get an idea of the this fish behavior.

Non- concerning reasons

For some species of fish, it is quite common to stay at the bottom of the tank. Some of them are instinctively bottom dwellers. Some of them may be too old and may not be able to swim all through the day and prefer to sit at the bottom of the tank.

Some common non-concerning reasons why your fish may choose to sit at the bottom can include

  • Bottom dwellers – Your fish may belong to the category of bottom dwellers. It is their typical behavioral pattern. Some examples of this type of fish can include loaches, plecos, and cory catfish. While you may see them moving up the tank, most of the time, they stay at the bottom.
  • Scavengers – Some fish belong to the genre of scavengers. That means they feed on the leftover food. These fish are also called bottom feeders.
  • Resting – Your fish may just be taking a rest at the bottom of the tank. You might have seen a few fish in your tank taking a rest at the bottom of your tank, and confuse them to be dead. If you have energetic fish in your tank, they may choose to take a little rest at the bottom of the tank between their active sessions.
  • Age – The age of the fish can also be a reason for its staying at the bottom of the tank. A typical lifespan of a fish is around 3 to 5 years. If your fish is aging, it may choose to stay at the bottom of the tank.

More concerning reasons

If you are noticing a behavioral change in your fish and your fish now prefers to be at the bottom of the tank, it can typically be due to a few reasons that may need to take some sort of preventive action.

Some of these reasons can include

  • Bullying or harassment – If you find a fish that is typically a top feeder or energetic suddenly begins staying at the bottom, it may be due to the bullying from its tank mates. It is possible that the other tankmates are harassing or nipping it. If that is the case, you may need to remove or replace the culprit fish that tends to bully other fish.
  • Overcrowding – Overcrowding in the tank can be another reason why your fish may decide to stay at the bottom. To fix this, you should try avoiding overcrowding of the tank or get a larger tank. You may also choose to mix the bottom and top dwellers.
  • Tank temperature – The temperature of the tank is a deciding factor when it comes to determining the fish behavior. If the temperature of the tank water is out of the range, the fish may choose to stay at the bottom. This is done specifically to conserve their energy.
  • Poor quality of water – A poor quality of water may make your fish get various diseases such as fungal or bacterial ailments. The fish chooses to be at the bottom of the tank as part of its survival instinct.

Can diseases make the fish stay at the bottom?

Yes, your fish may be inflicted with diseases, and that can be one of the reasons that it may choose to be at the bottom of the tank.

There are several diseases that can affect a fish. Some of them may include Ich (White Spot Disease), Velvet disease, Columnari, and Dropsy. That apart, you may also find some severe diseases which include Swim Bladder disease,

Swim bladder disease is one of the most worst diseases that can affect your fish. It is known to affect betta fish and fancy goldfish in many cases. This results in the swim bladder not functioning properly, thus limiting the ability of the fish to swim properly. This can make the fish swim on one side, swim upside down, or float at the top of the tank.

How can water quality make your fish sit at the bottom?

The water quality of your tank can have a say in your fish behavior. A bad quality of water or ammonia buildup can be one of the primary causes that may force your fish to lay at the bottom of the tank.

A water quality test should help you in fixing the issues that you may have with your water. It will reveal the ideal parameters and thus help you fix the issues if any.

The typical water parameters expected would be

  • Ammonia: 0 ppm (parts per million)
  • Nitrites: 0 ppm
  • Nitrates: Less than 20 ppm
  • pH Levels: Varies, but generally 6.5 to 7.5 for freshwater

You may also be interested in – The Ultimate Guide on How to Lower Nitrates in your Aquarium

A glance at why fish stay at the bottom of the tank

fish staying at the bottom

A close look at the tank should reveal the typical reasons for the fish staying at the bottom of the tank.

The table here should provide you with a better understanding of this context –

Category Description Recommended Action
Behavioral
Sleeping Bettas, among other fish, tend to rest at the bottom. Dim lights periodically.
Relaxing Fish may seek relaxation near the tank bottom. Monitor breathing and fin movements.
Bottom Dweller Certain fish species naturally inhabit the lower regions. No intervention is necessary.
New Environment Recently introduced fish may prefer staying low initially. Allow time for acclimatization.
Boredom Lack of mental stimulation can lead to behavioral issues. Enhance the habitat with foliage and toys.
Stress Various stressors can impact fish behavior. Check water quality and social dynamics.
Territory Conflicts over territory are common among fish. Provide additional hiding spots and barriers.
Hiding Fish may seek refuge if bullied by tankmates. Increase hiding places and assess tankmates.
Environmental
Wrong Temperature Rapid temperature fluctuations can distress fish. Monitor and adjust heating arrangements.
Strong Current Some fish prefer calmer water conditions. Regulate water flow to reduce turbulence.
Poor Water Quality Contaminants in water can adversely affect fish health. Regularly test water for pollutants.
Water Temperature Sudden changes in temperature can shock fish. Adjust heating and monitor thermal stability.
Water Quality Suboptimal water conditions can stress fish. Employ water quality testing kits regularly.
Tank Placement Ambient conditions like temperature and noise can impact fish. Relocate the tank to a more suitable environment.
Health-related
Sickness Illness can manifest in changes in fish behavior. Quarantine and treat affected fish promptly.
Ich Ichthyophthirius (Ich) can cause fish to seek the bottom. Treat for Ich and inspect for white lesions.
Diet Poor nutrition can lead to lethargy in fish. Upgrade to high-quality feed and monitor intake.
Tank-related
Lack of Space Overcrowding can induce stress among fish. Consider tank expansion or layout optimization.
Tank Mates Incompatibility with tankmates can lead to stress. Research species compatibility; separate aggressive individuals.
Quarantine Isolate sick fish to prevent the spreading of illness. Transfer sick individuals to a separate tank.
Hiding Spots Inadequate hiding spots can exacerbate stress. Augment tank with more vegetation and shelters.
Tank Size Insufficient tank size can contribute to stress. Upgrade to a larger tank or add supplementary tanks.

In Conclusion

There can be several reasons that may make your fish stay at the bottom of the tank. Analyzing your tank and the fish inside should help you arrive at the right reasons for the unusual behavior.

We assume the tips above should help you fix the issues and provide a perfect atmosphere for your fish to lead a healthy life.

About the author

Timmappa Kamat

Timmappa Kamat is a pet lover and a dedicated writer specializing in the captivating world of pets. He brings a wealth of knowledge and expertise to DreamyMammals. He grew up surrounded by pets since his childhood and this made him develop a connection with animals. This has sparked a lifelong curiosity for understanding and communicating with pets.
Writing style of Timmappa Kamat is characterised by a warm and friendly tone, making complex pet-related topics accessible to readers of all backgrounds. He loves sharing the animal behaviour with a persoanl touch. He creates articles that resonate with pet owners, thanks to their relatable and informative nature.

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About Author

Timmappa Kamat

Timmappa Kamat is a pet lover and a dedicated writer specializing in the captivating world of pets. He brings a wealth of knowledge and expertise to DreamyMammals. He grew up surrounded by pets since his childhood and this made him develop a connection with animals. This has sparked a lifelong curiosity for understanding and communicating with pets.
Writing style of Timmappa Kamat is characterised by a warm and friendly tone, making complex pet-related topics accessible to readers of all backgrounds. He loves sharing the animal behaviour with a persoanl touch. He creates articles that resonate with pet owners, thanks to their relatable and informative nature.