How Do You Humanely Kill Cardinal Tetras?

Fishkeeping is a great hobby, and we all want to keep our fish as happy as possible. Killing your fish is never a pleasant situation, but sometimes you need to do this for the greater good of everyone involved. So, killing a fish must be more cautious and less stressful than that already is. But, how do you humanely kill cardinal tetras?

There are many ways to kill your Cardinal tetras humanely. The first thing I would recommend is putting your fish in his own tank so he can swim free without being afraid of waiting until the last minute. If this isn’t possible for some reason, they don’t worry because there are still other ways you can humanely kill your Cardinal tetras.

However, in this post, we will talk about the reasons to kill your beautiful buddy intensely and how to do it most humanely.

What Is Humanely Kill?

Humanely kill is a term that describes how an animal dies after killing them. In the case of fish, humanely killing means not having them suffer from any pain or stress when their life comes to an end. A lot of people want this for themselves and also for the animals they may be slaughtering.

This is why you must know what humanely killing your fish means, how to accomplish this task, and have some tips on things you can do to ensure the process goes as smoothly as possible. So, with all of these elements in mind, let’s begin with our first question: Why do owners opt for humanely killing?

Why Do You Need To Euthanase Cardinal Tetras Humanely?

Cardinal tetras are beautiful fish that can allure your attention. So, why do the owners kill them? The death of your pet is always hard to accept, but when you choose to kill them. There must be sure enough a good reason for your action.

Thus, the reasons why people choose to kill Cardinal tetras humanely are:

Incurable Diseases

Cardinal tetras carry incurable diseases which are almost impossible to cure. It’s tough to watch your fish being ill and suffer from it until their death. Therefore, the owners might choose to kill them before their illness becomes worse or even contagious for other fishes in a tank.

Fish Attitude

Cardinal tetras are quite aggressive in nature. Therefore, you might find them fighting with other fishes in your aquarium. You might have to separate them from the group and keep them alone in a small tank which they can’t find any suitable company for their behavior. In this case, it’s better to end up their lives rather than keep them suffering until death eventually occurs anyway.

Inadequate Tank Size

Cardinal tetras are quite active fish that require more space to live. They can easily die due to a lack of oxygen if you keep them in a small tank without enough supply of fresh air into the water. In this case, you have to put them out of their misery.

How Do You Humanely Euthanase Cardinal Tetras?

To euthanase fish humanely means painlessly ending their life without making them suffer from it. Therefore, you mustn’t try any home remedies for killing the fish because they can be dangerous for your pet.

Besides this, some other ways to kill Cardinal tetras humanely are:

Freezing Them

The best way to euthanase Cardinal tetras is by putting them into a bowl with ice cubes and in a comatose state. Eventually, they’ll die due to suffocation or lack of oxygen supply in the water.

Putting Cardinal Tetras In A Bag And Drowning Them

This is another way to kill Cardinal Tetras without causing them any pain. You should take a bag or container and fill it with water. Then put the fish into that container /bag after putting some air in there.

The next step would be suffocating the fish by closing the opening of that bag/container. It will cause death within seconds due to a lack of oxygen supply.

Use Of A Lethal Drug

If you want to euthanase Cardinal Tetras humanely, then this is the best option for you. There are some lethal drugs available on the market that you can use for killing fish instantly and without causing any pain whatsoever.

Euthanizing Them

You can take your pet fish to any vet who will euthanize him for you in just seconds without causing any pain or suffering.

Euthanizing is basically the process of killing the fish by injecting them with an anesthetic. This method is very effective, but it can be dangerous too. So you should always use this method under the supervision and only if you have experience in doing so because otherwise, it could lead to serious consequences.

What Are The Chemicals Use To Humanely Kill Cardinal Tetras?

There are many chemicals and things that can euthanase Cardinal tetras. The most common chemicals in the home are:


Ammonia can have deadly effects on cardinal tetras. This substance is not something that would be around in the home. But if you ever had a fish tank with dead or decaying plants and/or animals, this could build up ammonia in your water, leading to death for the Cardinal Tetra.


Salt is a natural mineral that can also humanely kill Cardinal Tetras. It will dehydrate them, and they will die within minutes or hours you put them into salt water.


Alka Seltzer contains chemicals such as sodium bicarbonate, citric acid, and tartaric acid. These chemicals will cause the pH of the water to rise and lead to death for Cardinal Tetras in a matter of minutes or hours after you put into Alka-Seltzer-filled water.

Besides this, the substances Vets used to euthanize these fish are:


Benzocaine is a substance that will slow the heart and respiratory functions of Cardinal Tetras. You can use this to euthanase them in a matter of minutes or hours humanely. Benzocaine also has similar effects as Aspirin, which is why you need to give this orally to these fish without any harmful side effects.


This substance can cause death for Cardinal Tetras within minutes or hours after you put them into the water with Ketamine in it. This will also have similar effects as Xanax, which means you could give this to your fish orally without any harmful side effects.


What Is The Average Lifespan Of Cardinal Tetras?

On average, cardinal tetras can live up to five years if taken care of properly.

What Is The Minimum Tank Size For Cardinal Tetras?

If you have a small school of Cardinal tetras, they will need at least ten gallons each. If you want them to share the same tank with other fish, they need at least twenty-five gallons of water.

Can Cardinal Tetras Live With Other Fish?

Yes, cardinal tetras can live with other fish. But you have to ensure that the other fish will not harass them or eat their fins. However, they should be able to get along well together because they are very peaceful fish.

What Are The Common Health Issues In Cardinal Tetras?

The most common health issues that cardinal tetras can get are Ich and fin rot. But, besides this, you may also find some other problems like bloating, injuries, swim bladder diseases, etc. Thus, it is best to seek help from a professional if you see any unusual signs in your fish tank.


Summing up, it’s important to know that you can’t kill a Cardinal Tetra humanely if it doesn’t want to die. Since they’re such tiny fish, adding them into an aquarium without expecting them to live may not be the best idea unless you have other species in there for company and plenty of plants or decorations where they can hide.

I hope you enjoyed this guide and found it helpful.

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