How many fish can be in a 5-gallon tank?

In this article, we will answer the question “How many fish can be in a 5-gallon tank?” and also know the best fish species to keep in a 5-gallon tank and some of their tank specificities.

How many fish can be in a 5-gallon tank?

It is possible to keep a maximum of 4-5 small fish in a 5-gallon tank. There is a rule that says “one inch of fish per gallon of water”. However, this rule should only be taken into account when referring to smaller sized fish. Therefore, another characteristic of each fish species must be also considered.

Although many people think a 5-gallon tank is too small, some fish species can be great choices for this tank size. However, it will require you to take very thoughtful decisions about the tank structure and fish you will keep.

How to choose which fish can be in a 5-gallon tank?

To decide which fish species can be in a 5-gallon tank, it is important to consider three fish characteristics apart from the fish body size:

–       Temperament;

–       Schooling behaviour;

–       Social needs. 

Temperament

Some fish species are known to have territorial behaviours and can become aggressive towards other fish. Thus, it is important to learn about each fish species you are considering for your 5-gallon tank. Territorial fish are not suitable for sharing their space with other individuals.

Schooling behaviour

Some fish species have the behaviour to join conspecifics to swim in protective behaviour, even if they are the only species in a tank. Species that build large groups (bigger than 5 fish) are also not suitable for a 5-gallon tank. 

If you have decided to have a 5-gallon tank, you should consider not having schooling fish species (schools with more than 4-5 fish). This is because schooling fish can get depressed and stressed if alone or in small schools.

Social needs

There are also species that, although they do not form schools, can become stressed for being alone. 

What fish species can be in a 5-gallon tank?

We will now know which are the best fish to keep in a 5-gallon tank and some of their tank specificities.

Betta fish

The Betta fish is a good choice for a 5-gallon tank in various aspects. Betta fish are territorial, thus, they enjoy having their own space and will not feel depressed for being alone.

If you decide to keep a Betta fish, it is important to keep some live plants and décor for exploration activities for your Betta fish.

The recommended temperature to keep your tank water for your Betta is around 78 and 80 degrees Fahrenheit. Thus, you may need a heater and a thermostat. A filter is also needed to keep the tank water in good conditions for your Betta. 

The Betta fish appearance, personality and intelligence are the main reasons for the Betta being the top picks for 5-gallon tanks.

Guppies

Guppies are also a nice choice to keep in a 5-gallon tank. Although they are schooling fish, they are happy in small schools (4-5 individuals). As a 5-gallon tank has limited space, it is better not to keep females and males together. Otherwise, they will overpopulate your tank with lots of baby Guppies.

The recommended water temperature for Guppies is between 74 and 80 degrees Fahrenheit. You will also need a heater and thermostat, a filter and some lighting to keep this species in your tank.

Molly Fish

Molly Fish or mollies are relative to the Guppies. They are very peaceful and bright coloured, which makes them a very popular choice for 5-gallon tanks. You can keep up to 5 male mollies in a 5-gallon tank without having problems. They can have colours varying from black to green and gold. 

They are also an easy to maintain species and also very easy to find in aquarium stores. They require water temperatures between 74 and 82 degrees Fahrenheit. They do not require much, a heater, a thermostat, a sponge filter and some lighting are the main requirement to keep your Molly Fish healthy and happy.

Pygmy Corydoras

The Pygmy Corydoras are small peaceful catfish. Corydoras tend to live in schools, thus, only consider having the nano species, the Pygmy Corydoras. It is possible to keep up to 5 Pygmy Corydoras in your 5-gallon tank. 

This species can help you with tank cleaning and water quality maintenance. However, a small sponge filter is recommended to keep your tank in perfect condition. They require water temperature ranging from 72 to 79 degrees Fahrenheit. 

Neon Tetras

Neon Tetras are also an easy fish to maintain. They are small fish with bright colours. They are a good choice for beginners. They are very peaceful and live in small communities (maximum of 5 individuals).

The water temperature recommended to keep your Neon Tetras is between 74 and 80 degrees Fahrenheit. It is also recommended to keep plants and some décor as hiding spots.

Least Killifish

To keep the Least Killifish it is necessary to consider their active swimming habit. Thus, a 5-gallon tank would fit only 2 Least Killifish. If you consider this species it is recommended to keep a male-female pair. They will stick together forever. Although, you should get no more than one male for your tank. 

They are very easy fish to maintain and require low effort. The recommended water temperature is between 68 and 75 degrees Fahrenheit.

Celestial Pearl Danio

The Celestial Pearl Danio is one of the favourite choices for 5-gallon tanks. They are very peaceful and easy to maintain. They are not schooling fish. Thus, having 5 of them in a 5-gallon tank would not be an issue. 

They are hardy fish. However, there are some recommendations to keep well-being. The recommended water temperature is between 71 and 78 degrees Fahrenheit. They are cold-water fish. Thus, sometimes it can be possible to keep them without a heater or thermostat, although it is still recommended.

If you are considering having both sexes in your tank, opt for more females, 4:1 in the female-to-male ratio would be ideal.

Dwarf Pea Puffer

This species is also an easy to maintain one. Although they are very small fish, they are classified as aggressive. Thus, you should keep only one Dwarf Pea Puffer in a 5-gallon tank. They are very beautiful fish and has become very popular among aquarists.

The water temperature recommended for the Dwarf Pea Puffer is between 72 and 82 degrees Fahrenheit. They do not require much, a heater with thermostat, filter, and lighting. It is also recommended to have some plants to provide hiding spots.

Fish that cannot be in a 5-gallon tank?

–       Goldfish – a 5-gallon tank would be too small for this fish. In addition, they are big waste producers, which could affect their well-being and quality of life;

–       Angelfish – this species also gets too large for a 5-gallon tank. Also, they can get very aggressive and stressed if kept in a restricted space.

What are the top 5 best combinations for a 5-gallon tank?

1.   1 Betta, 1 Amano Shrimp, 1 Nerite Snail, and 2 Killifish;

2.   10 Cherry Shrimp and 5 Nerite Snails;

3.   1 Betta and 2 Cherry Shrimp;

4.   5 Chery Shrimp and 2 Thai Micro Crabs;

5.   4 Celestial Pearl Danios (1 male and 3 females) and 2 Cherry Shrimp.

What are the top 5 best plants for a 5-gallon tank?

–       Java Ferns;

–       Java Moss;

–       Brazilian Micro Sword;

–       Anubias;

–       Marimo Moss Balls.

Conclusion 

In this article, we answered the question “How many fish can be in a 5-gallon tank?” and knew the best fish species to be kept in a 5-gallon tank and some of their tank specificities.

If you have any thoughts or doubts, feel free to drop us in a comment below!

Frequently Asked Questions (FAQs): How many fish can be in a 5-gallon tank?

How many fish can go in a 5-gallon aquarium?

It is possible to keep up to 5 fish in a 5-gallon tank. However, these fish should not have more than 2 inches each. Also, consider the fish species behaviour and breeding possibility. Thus, only having one sex would be recommended in some cases. Fish larger than 2 inches are not recommended as they would have very limited space to swim. 

Is a 5-gallon tank big enough for 2 fish?

Yes, but the answer depends on what fish you are considering for a 5-gallon tank. You should opt for tiny species not bigger than 2 inches. Otherwise, the tank would be too small for them to swim.

How many guppies can you have in a 5-gallon tank? 

You can keep up to 5 Guppies in a 5-gallon tank. The minimum is 2 and the maximum 5, as they are schooling fish. Also, be aware they can reproduce and overpopulate your tank. Thus, having only males in your 5-gallon tank.

How many molly fish can you have in a 5-gallon tank?

Similarly to the Guppies, it is possible to keep up to 5 male Mollies in a 5-gallon tank. Avoid keeping males and females together as they may overpopulate your tank by breeding. 

Can you put a Goldfish in a 5-gallon tank?

Goldfish are not a good choice to keep in a 5-gallon tank. They are big fish and produce a lot of waste and could contaminate their water. Thus, the tank conditions to keep a Goldfish would require at least a 10-gallon tank.

What fish can go in a 5-gallon tank with a Betta?

The best tank mates for a Betta fish in a 5-gallon tank are shrimps and snails. However, it would be also possible to keep a pair of Killifish with your Betta.

References 

Best Fish For a 5 Gallon Tank (And Small Tank Benefits).  https://zenaquaria.com/best-fish-for-a-5-gallon-tank/#1_Betta_Fish_Betta_splendens

Best Fish For A 5 Gallon Tank Stocking Ideas And Combinations You Can Use. https://www.tropicalfishcareguides.com/aquarium-fish/stocking-a-5-gallon-tank

How Many Fish Can Be In A 5-Gallon Tank? Best Fish & Stocking Ideas. https://www.fishkeepingwisdom.com/how-many-fish-in-a-5-gallon-tank/

Sheppard, M. 2021. 21 Best Fish For 5 Gallon Tanks (With Pictures). https://www.aquariumsource.com/fish-for-5-gallon-tanks/

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