How Many Tetras in a 5-Gallon Tank?

There are many types of fish available in the world when you start counting them; you will most probably spend an entire day and more.

Speaking of kinds of fish, there is a specific kind that many lovers of aquatic life like keeping in their homes, and this is the tetra.

Tetra is a collective name used to refer to many small characiform fishes. They are mainly found in freshwater, and moving them to salty water/marine environments will significantly affect their survival.

How Many Tetras in a 5-Gallon Tank?

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How Many Tetras in a 5-Gallon Tank?

Many people love having tetras, but they do not know how to match the appropriate number of tetras to a container of a particular size. In this instance, we will take the example of a 5-gallon tank.

If you have been having such troubles, here is a guide to help you know how many tetras are supposed to be in a 5-gallon tank.

Types of Tetras You Can keep in a 5-Gallon Tank

While there are many types of tetras out there, not all of them can be kept in a 5 gallon fish tank. Below are the ones you can safely keep in a 5 gallon aquarium:

Ember Tetra

Ebmer Tetra

Ebmer Tetra

Ember tetra is one of the most common tetra types you will find in freshwater sources. It belongs to the characin family of characiformes.

Ember tetras feed on a wide variety of small foods like shrimp and crushed food flakes. The ember tetra can also feed on bloodworm and tubifex.

For the proper growth and development of ember tetras, make sure you only place seven or less of them in your 5-gallon tetra tank.

Any more will pose numerous challenges to their survival and may be catastrophic if proper adjustments are not put in place.

Neon Tetras

Neon Tetra

Neon Tetra

Just like the ember tetra, the neon tetra belongs to the Characin family. Its native can be traced back to the Clearwater streams in the Amazon Basin, South America.

There are also a lot of neon tetras located in Peru, Western Brazil, and Colombia. The fact that they love living in water with a temperature of between 20-degrees and 28-degrees might be the reason why they are mostly found in such areas.

Neon Fish are very conspicuous, and this is greatly attributed to their brightly-colored outer surface. The neon fish has a light blue back cover and a silver-white abdomen.

When you take a closer look at the sides of the fish, you will see a blue horizontal strip that runs from the nose to the fin at the back.

Neon tetras are known to be schooling fish, meaning they love to be in schools of other fish. This then means that it is not advisable to put a single neon tetra in a tank by itself.

You need to have two or more, but make sure that the number does not exceed five.

Lemon Tetra

Lemon Tetra

Lemon Tetra

Growing to a maximum length of 5cm, this small tetra fish is considered as one of the most preferred fish to have in an aquarium.

The body of an adult lemon tetra is usually translucent yellow. The anal and dorsal fins are a mixture of black and yellow.

When you get a closer look at the anal fin of the lemon tetra, you will get the impression of a glass-like appearance.

When using a 5-gallon tank, make sure you do not put more than five neon tetras so that each one of them can live comfortably.

Black Neon Tetra

Black Neon Tetra

Black Neon Tetra

In the list of tetras, the black neon tetras are probably one of the most basic fish in terms of outward appearance.

The elongated fish comes with a plain coloration of two stripes, one white and one black.

These two horizontal stripes are adjacent to one another and run from the fish’s eye to the base of its fin.

The fish prefers soft acidic water, and that is why its motherland can be traced to the Paraguay Basin in Brazil. It feeds on plants and small invertebrates.

When placing black neon tetras in a 5-gallon tank, make sure they are five or less.

Penguin Tetra

Penguin Tetra

Penguin Tetra

The penguin tetra is a characin fish that hails from the Amazon Basin in Brazil.

It is commonly traded by aquarium lovers under multiple names like hockey stick tetra, black-line penguin fish, and penguin fish, among others.

The black-line penguin tetra mostly feds on worms and crustaceans. You can also give it flake food and small insects.

In a 5-gallon fish tank, you can only place seven or less penguin fish.

How to Make a 5-Gallon Tetra Tank Work?

Now, that you know which tetras you can keep in a small aquarium, let’s see how to setup a stable system. Below are few things to consider when setting up a 5-gallon fish tank for tetra fish.

Establish Your Aquarium First

For you to have tetra fish in your home, you need an aquarium, which will be where they live and spend their entire lives.

The first step towards establishing an aquarium is looking through your options and choosing the appropriate fish tank for your tetra fish.

One thing has already been taken care for you, and that is the capacity; in this case, we will focus on the 5-gallon tank.

All you have to do is go for the design you want and ensure the tank meets the other specification you have in mind.

The next step is acquiring a proper stand that will handle the tank when it is full of all the content you intend to put in it.

Make sure that the tank is rated for a 5-gallon container, and it is steady (does not shake) as shaking may make the container topple over and may result in the death of the fish.

After everything is set, you need to decide where to place the aquarium. Where you place the aquarium has a significant impact on the health of your tetra fish.

Make sure the spot you choose is a place where the temperature remains consistent.

Make sure that the aquarium is not placed too close to the wall. Furthermore, make sure the spot is away from direct sunlight as this will cause excessive algae growth, which is not suitable for tetras.

Add a Good Filter

For the proper survival and thriving of your tetras, you need to purchase good filters which is suitable for 5 gallon fish tank. Filters play vital roles in tetra tanks. One of the roles is the removal of excess food.

When you feed your fish, and they fail to eat it all, you must remove the uneaten food since leaving it there many make the water dirty. A good filter comes in handy in such situations.

Dangerous chemicals in your tetra tank are a huge threat to your tetras, and therefore, you should do everything possible to eliminate them from the water.

The best way to go about this is by use of a filter. When you install a good filter, the removal of dangerous chemicals from your tetra tank becomes a walk in the park.

Fish are living organisms who release undigested food in the form of waste, and this process is what is called excretion. When fish excrete the waste remains in the water.

If the waste piles up, the water becomes toxic, and the fish may end up poisoning themselves.

That is why you need a good filter that will ease the process of removal of such waste.

Add Lots of Live Plants

The next thing you need to do after adding a filter in your tetra tank is looking for live plants and placing them in the tank.

Add as many plants as you can into the tank as they come with numerous benefits. For one, they produce oxygen for the tetra fish and absorb the carbon dioxide and ammonia the fish release.

When you have plants in the aquarium, the fish will always have a place (shelter) where they can go and settle when they need to rest or when they are tired of swimming around.

Plants also serve a great source of security for the tetras. The fish can go and hide between the plants every time they feel they are in danger.

It is common to have algae growing in your aquarium, but this does not mean that it is a good thing. Having lots of algae in your tetra tank is detrimental to the survival, growth, and development of your tetra fish.

That is why you need to do everything possible to hamper their growth in the tank. One of the most effective ways of doing so is by having lots of plants.

Plants compete with algae for nutrients, and the more plants you have, the more likely they will beat the algae and thrive.

Add Aquarium Lighting

Adding aquarium lighting in your tank is one of the most crucial parts of making your tank work. Lighting provides the necessary energy for the plants to photosynthesize.

The energy from lights is also important for the general well-being of the tetra fish. Lighting is also important for the growth of corals, fish, bacteria, and all the important living organisms in the aquarium.


Tetras are excellent fish to have in your home, but there is a lot that comes with the preparation and setting up of the tanks that they will use. One, you need to know which type of tetra you would like to have in your home.

This is because your choice plays a vital role in determining the number of tetras you can fit in a particular container. In this case, we took an example of a 5-gallon tank.

When you are going for a black neon tetra, you can only fit a maximum of five fish while in the same container, you can place up to seven tetra fish.

With that taken care of, you then need to know how to make a tetra tank work, and the first thing you need to do is establish your tetra tank.

Once that is done, you can move on and add a good filter that will help in clearing any wastes in your tank.

After that, add lots of live plants and then finish off by installing aquarium lighting.

Questions and Answers

Hi Fabian, Which plants does the Ember Tetras prefer, or is it any plants. Thanks a lot.

    You can use any aquatic plants with Ember tetras. They love a heavily planted environment and they won’t eat the plants, so you can use both fast and slow growing plants.

In a 5 gallon tank can I put live brine shrimp in with my 5 tetras or a couple of pigmy Cory fish?

    Most likely, the brine shrimp will get eaten by the neon tetras. What is your goal with this setup to keep the brine shrimp alive or to provide your fish live food?

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