Top 17 Best Nano Fish For Beginners By Size

Some of the best tank setups are also the smallest!

Nano fish come with many different brilliant colors and energetic personalities.

Lots of these fish are community-friendly and can live together or even cohabitate with some larger species.

Tiny fish can fill big roles that some of the larger fish cannot. They add a lively charm to the small spaces in your tank, and their eye-catching colors will draw attention to your underwater plants.

Are you considering some tiny fish for your aquarium?

Below we have listed the 17 most popular nano fish based on their size, ease of care and appearance…

Best Nano Fish

Species Beginner Friendly Price
Betta Fish Yes $6-$35
Cardinal Tetra Yes $3-$5
Celestial Pearl Danio Yes $10-$20
Cherry Barb Yes $3-$6
Chili Rasbora No $3-$5
Clown Killifish No $10-$25
Corydoras Catfish Species dependent $5-$25
Ember Tetra Yes $3-$5
Guppy Yes $15-$30
Harlequin Rasbora Yes $4-$6
Neon Tetra Yes $4-$6
Otocinclus Yes $5-$10
Rummy Nose Tetra No $3-$6
Sparkling Gourami Yes $4-$6
Swordtail Yes $4-$15
White Cloud Mountain Minnow Yes $4-$6
Zebra Danio Yes $2-$5

17. Zebra Danio

Zebra Danio

The Zebra Danio is one of the friendliest nanos around.

Their blue striped pattern can be seen from near or far, and is especially visible when the fish are in a large shoal.

It grows up to 2 inches long and needs at least a 10 gallon tank. It is extremely resilient and makes a good first pick for children and beginners.

This active fish loves to explore its environment with the other fish in its shoal and you will love watching it as it darts in and out of your plants.

16. White Cloud Mountain Minnow

White Cloud Mountain Minnow

There are many beautiful fish species available for tropical aquariums, but the White Cloud Mountain Minnow is one for temperate setups.

These fish are adapted to water temperatures as low as 60°F.

White Cloud Mountain Minnows have beautiful iridescent lateral lines and bright orange fins. They grow up to 1 inch long and school in groups of 6 to 10.

You can keep them with Dojo Loaches, Zebra Danios, and other temperate-water fish. They can even live alongside some warm-water fish, such as Fancy Guppies.

To set up a White Cloud’s home, you will need a 10-gallon tank lined with light-colored pebbles. The water must be completely clear and you should use an under-gravel filter to create a mild current.

15. Swordtail


The Swordtail is a delightful livebearer that can live in freshwater or brackish water environments.

It is known as the Green Swordtail but comes in many other colors. Color varieties include blue, red, purple, yellow, gold, and many more. There are some that are even designed to resemble a Goldfish or Kohaku Koi.

Swordtails get their name from their long sword-like fin that extends from their caudal fin.

They can grow to about 5 inches long, which makes them one of the friendly fish. Even at this size, they can be kept in a 10 or 15 gallon tank.

14. Sparkling Gourami

Sparkling Gourami Swimming

The Sparkling Gourami is the perfect nano Gourami.

This 1 inch beauty has a dazzling color that attracts attention from everyone.

Sparkling Gouramis have iridescent scales in turquoise blue shades. It is one of the most beginner friendly Gouramis too. They can tolerate a wide range of different salinities, acidity levels, and water temperatures.

This fish has a cult following among aquascapers who love to use them to add color to a planted tank. Its habitat can be decorated with Dwarf Hairgrass, Duckweed, or Water Ferns.

13. Rummy Nose Tetra

Rummy Nose Tetra

The Rummy Nose Tetra has one of the strangest color patterns of any Tetra species.

They have a splash of red over their snout which gives them the appearance of a bloody nose.

There are 3 different species: the True Rummy Nose, the False Rummy Nose, and the Common Rummy Nose. Since the species are so similar it does not really matter which one you have.

Each species grows to 2.5 inches long which is one of the largest Tetras you can get.

12. Otocinclus

Otto Catfish

An Otocinclus or Otto Catfish is an adorable Catfish.

They are best known as algae cleaners and only grow to a maximum size of 2 inches long.

There are 19 different species of Oto Catfish, and some of the most popular include: the Common Oto, Zebra Oto, Silver Oto, and Gold Oto. The most common color form is rocky gray or brown with a single black stripe which helps them blend in with the substrate.

11. Neon Tetra

Neon Tetra

Neon Tetras are among the most famous fish.

Just like the Cardinal Tetra this fish has a red body with a shimmering blue lateral line. However, the red color only appears on the ventral side.

Neon Tetras grow up to 1.5 inches long and will shoal in groups of 15 to 20. You should allow for 1 to 2 gallons of water for every Neon in your shoal.

In a large shoal they are bold and active and will not even shy away from larger fish.

10. Harlequin Rasbora

Harlequin Rasbora

The Harlequin Rasbora is the most popular Rasbora.

They look similar to the Chili Rasbora but they grow up to 2 inches. They have peach-colored bodies, black tails, and orange fins.

Unlike Chili Rasboras it spends most of its time out in the open. For such a little fish, it is not very shy at all. Tetras, Celestial Pearl Danios, Sparkling Gouramis, and other Rasboras make excellent tank mates.

9. Guppy


The Guppy is one of the most beautiful nano fish around.

You can find them in red, blue, yellow and orange. You may find two, three, or even four colors on the same fish.

In addition to the many available colors, there are also several patterns and designs. The Tuxedo, for example, includes a light color against a dark base. On the Lace variety the colors appear in an intricate lattice design. Snakeskin features a color pattern that resembles snake scales.

Guppies can live in a 5-gallon tank but will feel more comfortable in a 10-gallon tank where they can shoal. They can live alongside Platys, Swordtails, Rasboras, and Tetras.

8. Ember Tetra

Close Up Ember Tetra

Ember Tetras are tiny fire-colored fish that travel in schools of 8 or more.

They are less than an inch in length but their bright colors make up for it!

A school of 8 Ember Tetras needs a 10-gallon tank with a temperature of 68°F or above.

However, the larger your school of Ember Tetras is the more they will stand out. You can create an even more eye-catching underwater world by adding them to a community full of Neon and Flame Tetras, Harlequin Rasboras, and other brightly colored small fish.

They are sure to attract attention in a garden full of both rooted and floating plants.

7. Cory Catfish

Cory Catfish Close Up

When most people think of a Catfish they think of a very large fish with long whiskers.

However, the Cory Catfish is a friendly Catfish that grows up to 4 inches long.

They are often mistakenly kept as algae cleaners but they do not actually eat algae.

Instead these fish are meant to add life and color to the bottom of the tank. They come in iridescent green, spotted patterns, albino, pink, or even gold.

Corys will get along well with Tetras, Livebearers, Loaches, and Rasboras. They may even join a shoal of Tetras.

6. Clown Killifish

Clown Killifish

Most freshwater Killifish live in pools that dry up after the rainy season, so they only live for 1 or 2 years.

However the Clown Killifish does not have this problem.

This 1.5 inch Killifish lives in permanent bodies of water in the wild.

Clown Killifish need a 5 to 10 gallon tank with slow-moving water and a very quiet filter. They need lots of open space to swim around and school in. You can watch them chase each other around the tank, rush the surface, and even jump!

5. Chili Rasbora

Chili Rasbora

Chili Rasboras look like tiny chili seeds floating in the water!

At just under an inch long they are among the smallest Rasboras.

These nano schooling fish are easily startled by sudden movements and loud noises. They can even die of shock if they are distressed.

Their tank mates should be 2 inches or smaller and have a peaceful nature. Pygmy Rasboras, Guppies, and Celestial Pearl Danios are a few safe choices.

4. Cherry Barb

Cherry Barb Close Up

The Cherry Barb is a peaceful community fish.

It grows up to 2 inches long and can be found in many different shades from blush to cherry red.

A school of 5 must be kept in a 25 gallon tank.

They do not nip, so there is no risk in housing them with Gouramis and other long-finned fish. They will also fit in with Tetras, Rasboras, Loaches, and small Catfish.

3. Celestial Pearl Danio

Celestial Pearl Danio Swimming

Danios come in many sizes and colors.

The Celestial Pearl Danio is not only one of the smallest, but also one of the most beautiful.

In fact when it was discovered in 2006 its striking colors were mistaken for a photo manipulation. It features a white pearl pattern over an iridescent blue body.

Celestial Pearl Danios are true nano fish measuring only 1 inch long.

A light intensity of 3 watts per gallon helps make their glittering scales stand out even more.

2. Cardinal Tetra

Cardinal Tetra

The Cardinal Tetra offers a streak of bright red for your aquarium.

This shoaling community fish makes a great addition to any aquascape.

It grows up to 2 inches long and lives in groups of 6 to 8. Its bright red body and shimmering blue lateral line will be noticed in any freshwater tank.

Cardinal Tetras are great for brightening up the background of your aquarium and drawing attention to your plants. They love swimming in and out of Java Ferns.

1. Betta Fish

Blue Betta Fish

The Betta Fish may be the most famous fish of all.

This small but fierce fish is a type of Gourami that reaches about 2 inches in length.

You can find them in bright red, purple, blue, yellow, and turquoise colors.

All Betta fish need a 5 to 10 gallon tank.

It is called the Siamese Fighting Fish because it is extremely aggressive toward its own kind. However, they can learn to get along with small schooling fish such as Tetras and Rasboras. They should never be kept with their own kind or other Gourami fish.

Frequently Asked Questions about Nano Fish

Which nano fish is the easiest to breed?
The Guppy is considered the easiest nano to breed.

Most of the time it does not even need any help to breed. If you have a group of Guppies in your tank then do not be surprised to find several new additions over time.

How long do Nano fish live for?
Unfortunately, most nanos have short lifespans.

The average lifespan of any nano fish is about 5 years.

What are the smallest Nano fish?
The Ruby Rasbora (Paedocypris progenetica) is the smallest nano fish and one of the world’s smallest vertebrate animals. This fish is less than half an inch long and it can school in a 3 to 5 gallon tank.

How many fish can be kept in a Nano tank?
There is no real limit to how many fish can be kept in a nano tank.

You will just need to make sure each of your fish has enough space. When stocking your tank you will need to consider the size of each fish and their shoals, activity level, swimming distance, and personality.

Which Is The Best Nano Fish For You?

Keeping large fish can be fun, but you should not overlook all of the wonderful nano fish out there.

These fish are so tiny that you can fit a group of them into a 10-gallon tabletop tank. Their small size is compensated for by their colorful appearance and resiliency.

These are only a few of the many different fish out there but the fish on this list are some of the most popular for small setups. Hopefully our A to Z list of the most popular species has helped you pick the perfect fish for you.

Which nano fish have you raised in your tanks? Let us know in the comments section below…