how to comfort a dying fish

How To Make A Dying Fish Comfortable

When you have a tank full of fish, you’ll have to deal with death more often than you’d like. While you can’t pick up fish and comfort them like other pets, you can make their final hours more comfortable by optimizing their environment.

To make a dying fish comfortable, do the following:

  • Ensure the tank’s temperature and water quality are optimal.
  • Keep the tank out of sunlight or draughts.
  • Clean the tank to minimize health hazards.
  • Provide hiding spots in the form of plants, accessories, and rocks.
  • Quarantine the fish in a hospital tank so that it can die peacefully.

In severe cases of pain and distress, you might want to consider euthanizing your pet fish. To do so humanely, use a clove oil bath or Alka Seltzer, which leads to a quick, painless death.

What Are the Signs of a Dying Fish?

Before dying, fish display several behaviors that allude to their imminent death. The symptoms vary depending on the cause of death, but the most common signs include:

Gasping for Air

Fish that can’t breathe properly because of a lack of dissolved oxygen in the tank gasp at the surface. This is most commonly due to increased ammonia and nitrite levels. The water doesn’t hold enough oxygen for the fish to breathe, so they head to the water’s surface to find oxygen.

Eventually, the stress will be too much for the fish, and they’ll die. According to the Florida Department of Agriculture and Consumer Services, other factors that affect the amount of oxygen in the water include:

  • Temperature
  • Salinity
  • Atmospheric pressure

If any of these factors aren’t right within the tank, your fish will die through a lack of oxygen and will struggle to breathe before it happens.

Changes in Appearance

If you notice any changes to your fish’s appearance, it likely has a disease or sickness. In many cases, the changes come on suddenly and without warning, signifying your fish is at death’s door. Dying fish may develop:

  • White spots on the body or fins
  • Discolored gills
  • Bulging eyes
  • Skin lesions or sores on the body

The worrying thing about diseases and sicknesses is that many of them are contagious and can spread through the tank, infecting the rest of the fish. If this happens, you could lose your aquarium in days.

Loss of Appetite

When fish are about to die, they become stressed and lose their appetite. Fish need an ample supply of protein to stay strong and healthy. Without it, they become weak and die. Appetite loss is most commonly caused by:

  • Unsanitary water conditions
  • Vitamin deficiencies
  • Illnesses, including hole in the head disease, fin rot, and ich
  • Stress
  • Constipation

Fish are only small, so these things can be fatal for them. Just before they die, they’ll stop eating and become noticeably thinner.

how to help a fish die peacefully

Abnormal Swimming Patterns

Dying fish begin exhibiting strange swimming patterns, indicating they’re not well. Sick fish start swimming sideways, upside down, and struggle to swim altogether. This can be caused by pain or poor nutrition.

You can tell the difference between erratic and abnormal swimming, as your fish will appear unhealthy and stressed at the same time. Fish that swim erratically are simply exercising or escaping aggressive tank mates – they have the energy levels to do so.

Fast Gill Movements

Some diseases cause the gills to become covered by a mucus secretion, causing breathing difficulties. As a result, you’ll notice that your fish breathe more quickly than usual because they can’t consume enough dissolved oxygen into their lungs.

Rapid breathing’s also a result of high ammonia and incorrect pH levels, which, as we’ve already mentioned, quickly kill fish.

Behavioral Changes

Fish have personalities exhibited through how they swim, how they interact with other fish, and their activity levels. You’ll get to learn your fish’s behavior by watching how they behave in the tank. If any of them start exhibiting strange behaviors and start acting differently, there’s something wrong. Your fish are likely dying. 

Color Fading

Many fish lose their color when they’re close to death. This is due to a lack of nutrients and oxygen. If the water parameters in the tank aren’t suitable or you position the tank somewhere too dark, they begin to turn white. This indicates they’re close to death. Coloration issues are also due to:

  • Nutritional deficiencies
  • Poor oxygen levels
  • Stress
  • Illnesses
  • Infections

When fish become stressed, their endocrine system secretes corticosterone. The Journal of Fish Biology explains how this is a significant stress hormone responsible for color fading. However, color loss can be a natural part of the aging process.

How to Comfort a Dying Fish

Fish are more than just fish – they’re pets and much-loved family friends. Some fish pass quickly before you get the chance to do anything about it. Others become sick, and their health gradually declines. To ease their suffering and find out what to do when your fish is dying, follow these steps:

Regulate Water Temperature

As fish age and develop illnesses, they become more susceptible to stress due to temperature changes. Older, sick fish can’t regulate their temperature very well. They’re also less active, so they struggle to warm up by themselves and need help to stay comfortable.

Stress is one of the leading causes of death in fish and can speed up the dying process. Slight temperature changes are normal, but minimize them to avoid a painful or uncomfortable death.

You can achieve this by doing the following:

  • Keeping your fish tank out of the sun
  • Placing it away from draughts, air vents, and open windows
  • Maintain the temperature of the room your tank’s in  
  • Cover the tank to retain heat

Keep the temperature of your fish tank at the higher end of what they need to stop them from becoming too cold. The younger, active, healthy fish in your tank will be able to tolerate a slight temperature rise. However, ensure the water doesn’t get too warm, as the dissolved oxygen will decrease, risking the lives of your healthy fish.

Maintain Water Quality

Keep your dying fish comfortable by maintaining the quality of the water. Tropical fish tanks fare best when the pH is between 6.8 and 7.5. Any changes to these levels can cause your fish to become stressed, sending them into pH shock.

Similarly, if you allow the ammonia and nitrite levels to rise, your fish will have an uncomfortable few final days. Ammonia poisoning is an uncomfortable and often painful condition, causing your fish to develop burns and breathing difficulties.

Keep testing your water to ensure the parameters are stable at all times and act quickly if they become compromised.

Keep Out of Sunlight

We’ve already mentioned how you should keep your tank out of the sun because of the temperature. Direct sunlight also causes a harmful algae bloom. Algae make conditions uncomfortable for dying fish and take over the whole tank, unbalancing the ecosystem. You can also avoid an algae bloom by:

  • Reducing the light
  • Controlling the nutrients by removing decaying matter
  • Adding aquatic plants
  • Introducing algae-eating plants to the tank

Try to avoid changing conditions while you have dying fish, as they’ll experience discomfort from the unsuitable environment.

Clean Your Tank

Fish need a clean living space to be strong and healthy. Dying fish need the same thing to prevent them from becoming uncomfortable. Dirty tanks aren’t just unpleasant to look at, but they can be a health hazard. Several things can make your tank dirty, including:

  • Fish waste
  • Rotting food
  • Decaying plants and leaves

Because of the rising ammonia and nitrites, the amount of oxygen is reduced, so it’s difficult for your fish to breathe. This can exacerbate your fish’s sickness or health issues, causing unnecessary suffering.

Provide Rest

Dying fish need plenty of rest. A sick fish won’t have the energy to swim and move out of the way of other fish, so keep the room your tank’s in as quiet and peaceful as possible. Fish can hear sounds well, so noisy pets or children tapping on the tank will stress all creatures in the tank out while causing the dying fish to become sicker.

If there aren’t enough hiding spaces in the tank that your dying fish can retreat to, add some plants, rocks, and other decorative accessories, giving it space to be alone. This will help it feel more comfortable without the stress of other fish.

How To Help a Fish Die Peacefully

If you notice your fish is dying in the aquarium slowly and looks to be in distress, you might want to consider euthanasia to ease its pain. While this isn’t the nicest thing to think about, it’s essential for the wellness of your fish. If you’re wondering how do you help a dying fish, consider these euthanasia methods:

Clove Oil Bath

According to the American Veterinary Medical Association, clove oil is recommended as a humane way to kill dying fish. Clove oil contains eugenol, an anesthetic agent that puts your fish to sleep before it painlessly succumbs to the ingredients in the bath. To create a bath:

  1. Add a dose of 400 mg/l to water and mix it to emulsify the oil.
  2. If it doesn’t dissolve very well, mix it with a little bit of hot water and leave it to cool.
  3. Transfer your dying fish to the water and observe it to ensure it loses consciousness.

After a short while, the breathing should cease, and the fish will quietly succumb to hypoxia.

The timescale of death varies between fish, but leave it in the solution for at least two hours or overnight if you’re in doubt. Use a magnifying glass to monitor for signs of life before removing the fish from the solution and burying it.

Alka Seltzer

Euthanizing your fish with Alka Seltzer is quick and painless. When the tablets combine with water, the citric acid and sodium bicarbonate creates a chemical reaction that causes carbon dioxide bubbles to form quickly. It removes all dissolved oxygen from the water, killing the fish.

Once you add your fish to the water, it stops breathing within seconds, slipping away. There is thrashing, but this is a natural reaction to the chemical solution. Leave the fish in for 10 minutes after it’s stopped moving to ensure it’s died.

Euthanasia is only a last resort when the fish is genuinely suffering. It’s always best to let a vet take care of a dying fish, but sometimes the fish is too weak to survive the stress of the journey. Make sure you’re confident in what you’re doing before proceeding with one of the methods.

Should I Remove a Dying Fish from the Tank?

If one of your fish is dying, remove it from the main tank and quarantine it. When setting up a new tank for your dying fish, replicate your aquarium conditions as closely as possible and provide a few hiding spaces to make your fish feel comfortable. There are several reasons for quarantining a dying fish, including:

Reduces Stress

The main benefit of removing your dying fish from the main tank is that it stops it from becoming stressed out by the busyness of the aquarium. When they’re in a tank with other fish, they have to move out of the way, hide, and compete for food, which they likely don’t have the energy for.

There’s also the risk of a dying fish due to being bullied by stronger, healthier tank makes. If aggressive fish notice that a fish isn’t as active as it used to be, they may start bullying it to assert dominance. As mentioned, stress speeds up the process of death, but not before making sick fish even more unwell.

what to do when your fish is dying

Stops Sickness Spreading

Another good reason for quarantining a dying fish is that it’s not always easy to tell what it’s dying from. It could be age, or it could be due to a health condition. If this is infectious or contagious, the rest of your tank is at risk of catching the same thing.

Quarantining a sick fish allows you to hand-feed it, ensuring it gets the nutrition and sustenance it needs to be comfortable. It also allows it to swim in peace without the risk of stress and other triggers.

Prevents Decay

If a fish dies while you’re away from home, moving it to another tank means the decaying body won’t pollute the tank your other fish are in. Decaying and rotting matter contributes to rising ammonia and nitrites levels, poisoning fish, and polluting the water.

It doesn’t take long for poor water quality to affect all fish in the aquarium. While they may not develop health conditions, they’ll become stressed, which is just as harmful as diseases and sicknesses.

How To Dispose of a Dead Fish

You should remove your dead fish from the tank as soon as it dies. If you don’t, it’ll decompose and cause the ammonia and nitrite levels to rise, risking the lives of the rest of your fish.

Before removing your dead fish, check that it’s deceased first. Sometimes, sick fish appear dead, but their bodies have slowed down to conserve energy. While it may look dead, it’s suffering from extreme lethargy.

Similarly, Behavioral Ecology and Sociobiology describes how some fish exhibit thanatosis, which is a death-feigning strategy. Cichlids and betta fish are particularly prone to adopting this behavior. To determine whether your fish is dead:

  1. Check for breathing
  2. Observe the eyes. If they’re cloudy or motionless, the fish is dead
  3. Feel the body for stiffness
  4. Check for a foul odor, which is a sign of decay
  5. See whether the fish is floating or sinking in the tank

When disposing of your dead fish, never flush it down the toilet. This is unhygienic and causes problems for local wildlife. Instead, there are various other disposal methods you could use, including:


The most hygienic method of disposal is burial. Whether you choose to have a backyard or potted plant burial is up to you. Burying your fish somewhere close by makes owners feel more comforted, and the decaying body provides nutrients for plants and flowers.


If you don’t have a garden or don’t like the idea of burying your fish, you could put it in the waste bin instead. While this isn’t a sentimental burying method, it gets rid of the fish cleanly and safely. However, wrap the fish in a muslin cloth or put it in a box. On a hot day, the body will decompose more quickly and attract flies and other wildlife.


If you have a compost bin, consider burying your fish in there. Burying it deep into the compost pile will hide the odor, minimizing the risk of animals getting to the body.


Many owners prefer to cremate their fish as it’s a more hygienic disposal method. You can safely cremate your fish at home or take it to a local pet crematorium.

It’s much harder to comfort dying fish than other animals. While there’s only so much you can do, making the conditions as comfortable as possible prevents stress, allowing your fish to have a more peaceful final few days.

Keep an eye on your healthy fish to make sure they’re not too affected by the presence of a sick, dying fish. If they are, it’s time to quarantine the dying fish into a hospital tank, where you can keep a closer eye on it.