How to Treat a Sick Fish in An Aquarium

How to Treat a Sick Fish in An Aquarium?

How to Treat a Sick Fish in An Aquarium?

Sometimes fish also become the victim of diseases just like every living creature gets sick multiple times in their lifetime. Fish can get sick by any of the diseases like an infectious disease, parasitic disease, or some other naturally curable disease.

Sometimes it is not actually a disease but a symptom of any body issues like constipation, injuries, or any congenital abnormalities. A fish can also get some viral disease as well which is highly contagious and need to be cured as soon as possible.

Here is a quick chart for some specific sickness that your aquarium fish get along with their treatment;

Fish Disease  Treatment Prevention
Bacterial infections Isolation, antibiotics addition in water Quarantine pet fish with these infections, maintain proper water quality  
Viral infections Treat affected areas on fish skin with a disinfectant, add formalin solution. Avoid contaminated food, clean water properly, Use medicated fish food
Parasites Treat fish by adding aquarium salt, or malachite green Separate the fish quickly, remove food leftovers from the tank
Itching Treat by adding aquarium salt, or copper sulfate Check for white spots on the fish body from time to time.
Poor Quality water Treat aquarium water with ammonia remover, do little changes, Test water quality frequently, use proper aeration in the tank

How to Treat a Sick Fish in An Aquarium?

It is necessary to treat a sick fish either its sickness is serious or not. It’s your moral duty to take care of your pet fish. If there is an infectious or viral disease to one of your pet fish, then it can spread in the entire tank and all of your fish can get infected.

Infectious diseases are very important to cure otherwise it can lead fish to death. A fish that is sick should be quarantined in a separate aquarium. It will protect other fish for getting the disease. After your pet fish get recovered from the disease, you can move it back to the aquarium with other fish.

Find Reasons for disease spread in Aquarium

Most of the diseases in aquarium spread because of bad quality water. So, if your pet fish are not happy swimmers then you should first check out the water conditions in your aquarium. Check that if there is too much ammonia in water.

Or the water appears to be clean but it has heavy metals in it. Sometimes the unwashed substrate, plants, toys, and other aquarium accessories can be the reason for pH change and diseases as well.

Partial water changes can be great in these cases to keep pH normal and water clean. You must keep your aquarium water clean because prevention is always better than cure.

Check out all of the water parameters first and then understand the reason for the problem which is causing issues to your pet fish. Also, make sure that your aquarium is not filled up with extra uneaten foodstuff which is getting decomposed by bacteria. Those bacteria are also the reason for disease spread in an aquarium.

How to identify a sick fish in an aquarium?

First of all, it is a must to identify a sick fish in an aquarium. There are different diseases that your fish can get and every disease has definitely its symptoms. Just you need to understand that what has happened with your fish.

It is an essential step that you have diagnosed the sick fish first ad observation is the main key. You can easily identify a sick because of its behavior which can be;

  • Swimming in an abnormal manner
  • Not eating properly
  • Color fading gradually
  • Laying in the bottom of the tank

Sometimes fish also show abnormal behavior at the time of spawning. But soon it lay their eggs and you got the thing that there is no disease.  But you have to consider other factors like dull color, gasping, no proper eating, etc. in a fish which is sick.

Changes in fish behavior can be the reason for stress, bad water or any real disease.

Check for any Sickness

Check out for any of the sicknesses in your pet fish. The symptoms which appear in it are;

  • Open sores
  • Red streaks over the body
  • Gasping
  • Bulging eyes
  • Flared fins
  • Lethargic and slow
  • Bloated appearance
  • Cloudy eyes

Bacterial infections can be treated if tackled right on time. But an infection is spreadable, if one fish is the victim, it can spread the infection to all of the other fish in the tank.

Bulging eyes

The symptom of bulging eyes and flared fins is not always an indication of a bacterial infection, it can be a sign that your fish has fought with other fish for space or anything else.

But in a diseased case, this condition is known as the Popeye disease in aquarium fish. Basically, it is the swelling, the reason for which is the fluid leaking in the area behind fish eyeballs. It causes a discolored eye or cloudy appearance inside fish eyes.

Torn fins

Besides fighting the other reason for the torn or clamped fins or torn fins is the cold water. This condition is termed as shimmies in which swim but don’t move back and forth. They are still at their place.

In this situation, fish fins get a little bit torn, and sometimes they are clamped. If you change the water and maintain its temperature at normal levels then you can cure the fish.

Abnormal swimming

You might have seen that sometimes your fish is not swimming normally. It gets bumped into different objects and didn’t register things.

This situation is not alarming always as this could be the reason for external parasites. Also, check for any swim bladder issues in fish.  You must investigate if your fish has changed its swimming behavior.

Along with this, your fish starts scratching itself with some rock or an object, it is also called as flashing.

Check for any Bacterial infection

In this situ, fish need to be isolated from other fish as soon as possible. 

Red lines on the skin

If your fish has red lines over the surface of its body then it indicates that there are some bacteria in the aquarium water which are causing infection in fish.

White spots

Small white spots appear on the surface of the fish if it is really sick. These spots can be treated but first separate your fish from all others who did not have the white spots.  

A certain species of bacteria are responsible for this infection that results in spots and sometimes discoloration too.  This also occurs when the aquarium fish has TB.

Fungal disease identification

There are different sickness symptoms in case of any of the fungal infections. Like the strange swimming patterns along with darting behavior.

There are also small collections of whitish material growth on the fish body, especially around the mouth, inside eyes, and around the sexual part. The whitish accumulation would be visible to you clearly.

Presence of any Parasitic infections  

The symptoms of parasitic infections are different from all of the other diseases that fish get. You can treat internal parasites in the fish. The symptoms which your pet fish shows in case of any parasitic disease are;

  • Scratches
  • Unusual mucus on body surface
  • Parasites or visible spots over the body surface
  • Abnormal breathing patterns

How to prevent fish sickness?

A fish sickness can be prevented in an aquarium if you will take some precautionary measures. Because it is a famous saying that precaution is always better than the cure you do after a disease.

First of all, you should know that whichever disease your fish has got, the bad quality water is the main cause of reducing your pet fish immunity.

A pet fish is vulnerable to be attacked by any of the disease, parasitic, fungal, or any other one just because of low immunity.

Otherwise, every living creature faces sickness. One with a high immunity system survives the most and lives in a better condition to defend against all diseases by themselves.

As the basic preventive measures, you should keep the water clean, its pH and temperature should be maintained.

Practice giving good and nutritious food to your fish to keep it healthy and protected from diseases. It should not be exposed to high levels of ammonia or nitrates.

If your fish has got the disease then quarantine it before the spread of disease in all of the fish. You can use tank filters to keep your tank water clean.

How to Treat Fish Sickness?

You can definitely help your fish to get recovered from sickness. Now, what measures you can do to treat the sickness of your fish are following.

Aquarium salt

Now, this thing is considered a therapeutic medicine for your fish. Aquarium salt is used for a fish cure from diseases and infections. This special salt for fish can soothe the symptoms of infections in your fish.

You can easily get this salt from Amazon. But first, you need to quarantine your fish which has the infection. You can set up a hospital fish tank and then add salt in water for your fish. Keep the fish there for 10 days and observe that if the signs of disease are fading away or not.


Medicines and injections are also used to treat some specific illnesses of fish. If a fish vet has suggested any of the medicine for your fish then you should use it.

Always use medication with caution. The amount of dosage given to treat a fish should be used as the vet suggested. The usage instructions are also given on the medicine itself.

You should start medication first you have diagnosed the issue. As some of the people starts giving medications and the only issue is the problem with parameters.

Temperature adjustments

Most of the parasites develop their life forms inside the aquarium when there is a temperature change. The temperature adjustments and controls are really important and in actual it is definitely a treat.

Partial water changes can keep the temperature and pH normal and water would be clean from ammonia and nitrates.

Remove activated Carbon

Remove activated carbon from the aquarium first. Check out that if there is any activated carbon inside the water. If yes then remove it and then add any medicine. Otherwise, activated carbon has the capability to remove any medicinal effect from the water.

So there is no use of any of the medicine if tank water has some activated carbon it. So, remove activated carbon and then add any medicine in fish water so that your fish can get the benefit and become well soon.

Monitor for 10 days

Monitor the sick fish in the hospital tank or anywhere where you have separated it for 10 days at least. Observe it properly that either its condition is getting well day by day or not. Keep all of the conditions of your fish aquarium to the best levels as much as you can.

Like the regular small amounts of water changes, temperature, and pH maintenance. You can use a magnifying glass to observe your fish properly. Observe the fins of your fish with this magnifying glass for any damage.

Also, observe that the spots on the fish body have gone or not. Your sick fish will get cured earlier like this if you are keeping such great care of it.

Final words

After reading this entire guide, you must be able to treat your fish yourself. Just understand things slowly and apply them to care for your fish.

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