25 Small Freshwater Fish Perfect For Your Home Aquarium

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Written By Matt Stevens

Hi, I'm Matt! I've been obsessed with fishkeeping for over 15 years now and created this site to share my knowledge with others.

Looking for the next member of your beautiful nano tank? Well, that’s never going to be an easy decision, considering the wide range of options in the pet industry.

So, this guide will walk you through the list of the 25 best small freshwater fish breeds. Our list includes some of the most sought-after nano fish that have become a staple name in the aquarium hobby, along with a few lesser-known varieties that deserve more attention from fish lovers.

All in all, it should help you solve the puzzle around small freshwater fish.

Let’s get started;

1. Neon Tetra

Neon Tetra is well-deserving of its cute name thanks to its colorful body with brilliant red and blue stripes.

Neon tetra swimming in fish tank.

An iconic figure in the aquarium community, this Tetra fish originates from the Amazon River basin and is one of the tiny-bodied freshwater varieties easily identified by the alluring body markings.

Neon Tetras can be kept in groups as a typical shoaling fish, readily accentuating any tank as part of a lively community.

Many aquarists know them for their resilience, enormous appetite, and less demanding traits in captivity.

So, if you need a small freshwater fish that lives up to the hype, this is probably the best time to get a colorful Neon Tetra.

Size: 1.5 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

2. Guppies

Guppies need no introduction to the aquarium community, and it’s little surprise they appear on our list of the best fish that do well in small tanks. 

Admired for their low maintenance and peaceful temperament, it’s hardly surprising many fish lovers have considered introducing them to their micro aquariums at some point.

Guppies have been bred for their attractive color combinations. But that’s not the only reason you may want to keep them at home.

They are only 2 inches long, yet flashy and less demanding, and can easily light up a boring aquarium.

But if you are going to introduce them to a home aquarium, keep them in small groups of at least 5 species at a time. Also, ensure the female population is higher than the males to limit their potentially aggressive behavior.

Size: 2 inches

Difficulty: Easy

Minimum Tank Size: 5 gallons

3. Betta fish

The show-stopping Betta has quickly become many people’s favorite small freshwater fish without even breaking a sweat. 

Veiltail Betta swimming in tank.

Bettas will always want to show off in the right environment, flaring their attractive gills and fins as onlookers give a seal of approval.

Selective breeding has created multiple color variations within the Betta family, but this doesn’t take anything away from their majestic appearance.  

The male Betta fish are particularly stunning, with free-flowing fins that are just so addictive to watch. Typically, the adult Betta fish have the added advantage of being extremely hardy.

But that doesn’t mean you should compromise the tank water conditions if you keep them at home.

Size: 3 inches

Difficulty: Intermediate

Minimum Tank Size: 5 gallons

4. Swordtail

Rightfully named for the beautiful, expansive tail fin, Swordtail fish could be all you need to revive a dull aquarium. 

swordtail fish swimming.

While their names can be intimidating, Swordtails aren’t aggressive and will be an excellent addition to a community tank.

Not many live-bearing species fit the profile of an ideal pet fish, but Swordtails certainly do, with a fulfilling personality that goes beyond their peaceful temperament.

At only 4 inches long, Swordtails will be more comfortable in their typical schooling community.

The intricate details all over their bodies deserve a special mention, which is why they are one of the most sought-after small freshwater fish in the aquarium community.

Size: 4 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

5. Platy

Platy fish is another small, long fish that has built a sizable following in the fishkeeping world.

They are the typical “old guards” of the aquarium hobby, with a long history spanning over 100 years.

With their laterally compressed bodies and exciting color variations, it’s easy to see why the Platy fish are easily becoming a common name in the pet industry.

Even though everybody admires their sleek body profiles with limitless color variations, we find the Platies’ easy-going personality and natural hardiness even more appealing.

And just like most types of small freshwater fish, they are perfect for starters. However, the Platies are known to eat their eggs during breeding. So, constant monitoring becomes an integral part of effective care in captivity.

Size: 3 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

6. Common Molly

freshwater Molly is a beautiful omnivorous fish that gets plenty of attention for all the right reasons. They are friendly and undemanding and should never miss inside a peaceful community tank.

molly fish

They can reach about 2 inches with ideal conditions, but their small size only contributes to their sparkly appearance in captivity.

Mollies are endemic to South America’s coastal brackish waters and freshwater streams, and the fact they can coexist with most species readily makes them an exciting prospect at home.

Keep them with Platies, Guppies, or Tetras, and you might have just found the secret to creating an eye-catching aquarium without breaking the bank. 

Size: 4.5 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

7. Cory Catfish

Cory Catfish might be the most popular species of the catfish family. It is a small fish for a small tank with flexible requirements in captivity. 

cory catfish swimming in tank.

Inhabiting different parts of the beautiful South American continent, Cory Catfish typically exists in shoaling communities.

They bring a ton of personality to community tanks and being the typical bottom-dwellers, can live peacefully in captivity, completely unbothered by the daily activities.

With many color variations and exciting patterns, you will be spoilt for choice if you settle for the Cory Catfishes as an ideal pet fish.

Also, they will outlive most freshwater aquarium fish, which is why you should only consider them if you can make a long-term commitment.

Size: 4 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

8. Harlequin Rasbora

Not every day do we find a tiny fish that’s quite addicting to watch in captivity yet so happy to stay in large groups. 

But such is Harlequin Rasbora, a popular schooling fish whose presence in the aquarium community has been met by lots of praises from fish lovers of different backgrounds.

You may never be fully convinced of their ability to light up your aquarium until you keep them in colonies of up to 6 species.

But as much as keeping Harlequin Rasboras at home appears exciting, always ensure the water conditions are good enough to support their lives. And if it’s the tank size, the general rule states, you should never go below the standard 1 gallon for every two fish.

Size: 2 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

9. Sparkling Gourami

If it’s all about elevating the look of your aquarium, you won’t find many better options than the Sparkling Gouramis.

sparkling gourami swimming in aquarium.

Hailing from Southeast Asia’s small, forested freshwater rivers, these fish have a high survivability rate, always appealing to newbie aquarists.

They are relatively peaceful and display eye-catching dark coloring with vivid spots all over their bodies. Besides, Sparkling Gouramis can live for 5 years with quality care and prefer a well-planted aquarium with ideal tank mates.

For someone who’s never kept a beautiful member of the Osphronemidae family, the charming Sparkling Gouramis, also called the Pygmy Gouramis, would be an excellent option.

Size: 1.5 inches

Difficulty: Easy-Moderate

Minimum Tank Size: 15 gallons

10. Otocinclus

Otocinclus” is a name many aquarists may struggle to pronounce, but this distinct-looking freshwater fish has everything it takes to become your dream pet fish.

Otocinclus Catfish swimming in tank.

Heavy eaters yet docile for the better part of the days, you can trust the Otocinclus, sometimes called Dwarf Suckers, to clear unwanted algal growth inside the tank.

Many people love them for their attractive, cylindrical-shaped bodies, but their small sizes also mean they will be easy to care for at home.

With just a small, 10 gallon tank, a neutral pH, and soft water, you will have created an ideal environment for your Dwarf Suckers.

Size: 2 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

11. Apistogramma

Apistogramma is commonly called Dwarf Cichlid and is one of the best tiny fishes we constantly recommend to aquarists.

They are peaceful fish, a trait rarely seen in the broader Cichlid community. And while their stunning bodies will make them attractive, you will instantly realize that their care requirements in captivity are even more impressive.

Unlike most Cichlids, the Apistogrammas readily cohabitate with other peaceful fish as long as the newcomers stay at the upper and middle parts of the aquarium.

You will spot exciting color patterns in the Dwarf Cichlid community, some awe-inspiring. Their standard size is 3 inches, and the basic care guidelines involve an ideal tank setup, usually 20-30 gallons.

Size: 3 inches

Difficulty: Easy-Moderate

Minimum Tank Size: 20-30 gallons

12. Celestial Pearl Danio

Celestial Pearl Danios never grow beyond the 1-inch mark in captivity and are one of the best small freshwater tropical fish to have at home. Perhaps you will recognize them from their perfectly rounded bodies with large, glittering eyes.

Celestial Pearl Danio

But if you want to introduce them to a community tank, never forget that a typical Celestial Pearl Danio likes its habitat natural with enough vegetation and multiple hiding spots.

Celestial given name originates from the beautiful galaxy appearance that’s so dominant all over their bodies, and you can fondly remember them as the Galaxy Rasboras.  

Typically, Celestial Pearl Danios are non-aggressive species that enjoy each other’s company even though they are never a natural schooling fish for aquariums. 

Size: 1 inch

Difficulty: Intermediate

Minimum Tank Size: 10 gallons

13. Peacock Gudgeon

A small aquarium fish getting its name after the majestic Peacock bird only confirms one thing; Peacock Gudgeon is stunning.

They inhabit the free-flowing waters of New Zealand and Papua New Guinea even though other species have been discovered in Australia.

Their gorgeous-looking, slender bodies with well-rounded heads stand out in any environment. And their vivid colors won’t fail to capture your attention in captivity.

Color variations are pretty normal in the Peacock Gudgeon community, even if most species take the standard iridescent blue base pattern.

With the best possible conditions, Peacock Gudgeons will reach their optimal sizes at only 3 inches in captivity. Of course, they can only flourish in groups, being the stunning, small shoaling species.

Size: 3 inches

Difficulty: Easy-Moderate

Minimum Tank Size: 15 gallons

14. Chili Rasbora

Oh! Well. The Chili Rasbora was always going to be on the list of the best freshwater fish for small tanks.

Chili Rasbora swimming in a fish tank

Why? Because they are a cute little nano planted tank fish with a beautiful pink and red coloring that always stands out from the crowd.

Naturally, Chili Rasboras are a rather shy fish that will want sufficient time to adjust to a new habitat. Their daily routine involves excessive hiding even though they can feel more comfortable in groups.

Usually, Chili Rasboras are kept in colonies, swimming together in unison while giving free entertainment to curious onlookers.

What’s more, Chili Rasbora’s staple diet entails high-quality dried foods, but they can also benefit from the typical protein-rich types like daphnia, brine shrimp, and bloodworms.

Size: 0.7 inches

Difficulty: Easy

Minimum Tank Size: 5-10 gallons

15. Cardinal Tetra

Cardinal Tetras are widely praised for their impressive schooling abilities and low maintenance in captivity. They are arguably one of the most beautiful Tetra fish and exciting addition to community tanks.

Cardinal tetra swimming in tank.

While they present unique challenges during breeding, the fine-looking Cardinal Tetras can accentuate any tank, provided the care guidelines match their minimum requirements.

In the wild environment, Cardinal Tetras are commonly found in the South American Rio, Orinoco, and Amazon rivers, where they swim in slow-moving waters in murky environments.

In terms of general appearance, Cardinal Tetras are simply stunning, displaying vivid neon blue bars from their noses to the tailfins, with another red stripe complementing their smooth appearance.

At only 2 inches long in full maturity, it shouldn’t be hard to create a dream aquarium with an enticing school of Cardinal Tetras.

Size: 2 inches

Difficulty Level: Easy

Minimum Tank Size: 15-20 gallons

16. Killifish

A Killifish is a little aquarium fish exclusively found in warm water climates. They are a live-bearing species with a widespread population in South America, Central America, and the USA.

golden wonder killifish swimming in fish tank.

A typical Killifish only measures around 1.5 inches long in captivity, making them an easy target for large-sized fish. That’s why they only thrive in groups.

Besides, the Killifish take on brilliant colors with slender bodies. The male fish appear larger than the females, and most species will be peaceful when kept in fancy aquariums.

As with most species, the male Killifish can get somewhat aggressive to one another, and keeping them in a crowded environment can only worsen the situation.

But as long as you create a sizable aquarium with ideal water parameters and suitable tank mates, you can keep them for as long as it’s feasible.

Size: 1.5 inches

Difficulty: Easy

Minimum Tank Size: 5 gallons

17. Dwarf Gourami

Dwarf Gourami ranks highly among the most popular small freshwater fish for a reason. A typical species is shy yet peaceful and happy to thrive as part of a larger community.

Dwarf Gourami swimming in tank.

Dwarf Gouramis have the iconic labyrinth organ, meaning they can comfortably breathe on the water surface. If you keep them in pairs, they will want to swim in unison, creating an exciting pattern that’s never seen in most freshwater fish.

 “Dwarf” in their name denotes their small body sizes, with a typical adult only measuring about 2 inches, but that doesn’t compromise their natural beauty in captivity.

Typically, an adult male Dwarf Gourami boasts a bright orange-red base coloration with beautiful stripes running towards the fins. On the other hand, the females take on a more faded, silvery blue-gray coloring that naturally makes them less conspicuous.

Size: 4.5 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

18. White Cloud Mountain Minnow

White Cloud Mountain Minnows are small, attractive fish that have been famously compared to the Neon Tetras. They originate from China’s White Cloud Mountains with interesting color markings and slender bodies.

White Cloud Mountain Minnow

We’re not surprised by their popularity in the aquarium trade, being ardent lovers ourselves thanks to their affordability and stunning appearance. They take on a vivid bright blue coloration with specific care requirements.

For a small, 2-inch long fish with a playful temperament, it’s only fair to keep White Cloud Mountain Minnows in colonies of up to 6 species at a time. On the other hand, the tank size is best maintained at 10 gallons and above.

Size: 2 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

19. Zebra Danio

Zebra Danios are a beautiful nano fish and an exciting option for many reasons.

Zebra Danio swimming in tank.

They have the natural Danio appearance, and even though their bodies take on plain coloration, they are always fun to include in a peaceful community.

Their striking black and white stripes make them stand out in captivity, and anyone who loves the small-sized Danio fish shouldn’t look elsewhere.

Of course, the Zebra Danios are best kept in large groups where they effortlessly display their impressive social behavior and shoaling abilities.

They won’t outlive many species in captivity, which implies you should make the most of the little time you get with your beautiful Zebra Danio buddies.

Size: 2.5 inches

Difficulty: Easy

Minimum Tank Size: 15 gallons

20. Serpae Tetra

Serpae Tetra is a small freshwater fish with a unique attribute; an easy-going personality. They are brilliantly colored fish with beautiful red fins that add a unique style to any aquarium, especially when kept in groups.

Serpae Tetra swimming in aquarium

They are peaceful and active, and not even the occasional fin-nipping tendencies can stop aquarists from introducing them to their community tanks.

Serpae Tetra’s beautiful bodies have earned them other cute nicknames like the Red Serpae, Blood Characin, Red Minor Tetra, Serpa Tetra, and Jewel Tetra, among the rest.

As long as the water parameters stay within the recommended levels, nothing should stop you from creating a beautiful Serpae Tetra community.

Size: 1.75 inches

Difficulty: Easy

Minimum Tank Size: 20 gallons

21. Panda Corydora

Panda Corydora might be the most sought-after freshwater fish of the Callichthyidae family. At first glance, you will be deeply absorbed into their beautiful bodies, featuring white or translucent base coloration with complimentary black spots.

Panda Cory (Panda Catfish) Species Profile

They are small, bottom-dwelling fish, famous for their friendly temperament. And just like most small freshwater fish, they only flourish in groups.

Aside from their charming personality, another interesting attribute of the Panda Corydoras is their impressive lifespan. A typical species can live for up to a decade with quality care, despite only reaching maximum sizes of 2 inches in captivity.

Size: 2 inches

Difficulty: Very Easy

Minimum Tank Size: 10 gallons

22. Glowlight Tetra

Glowlight Tetra had to appear on our list because how do you ignore such a sparkling freshwater fish with a low maintenance tag?

Glowlight tetra swimming in tank.

Glowlight Tetras are among the few species with natural color markings, never to be confused with the common genetically engineered freshwater fish.

While we could go on and on to mention their most impressive attributes, we find their gorgeous bodies more alluring.

They inhabit the Guyana Rivers of South America and are insanely hardy and interesting to care for.

As for the general appearance, Glowlight Tetras assume the typical torpedo-shaped body pattern, with a silvery base coloration and a beautiful orange-reddish stripe.

Size: 1.5 inches

Difficulty: Easy

Minimum Tank Size: 10 gallons

23. Tiger Barb

Tiger Barb, famously called Barbus tetrazona in scientific contexts, is an eye-catching, small barb fish that’s surprisingly easy to care for. Their names can be intimidating for obvious reasons, but it is just that, a name.

Tiger barb swimming in tank.

So, don’t let their four, distinctive tiger-like stripes on the beautiful orange-yellow bodies stop you from enjoying a satisfying fishkeeping adventure.

Of course, they can be aggressive, especially with the wrong tank mates. But you can easily prevent that by introducing them to the right habitat with a balanced diet, suitable companions, and ideal living conditions.

On average, adult Tiger Barbs measure about 2-3 inches in full length. So, they are large enough to steal the show inside the aquarium but only small enough to rely on a schooling community for security and comfort.

Size: 3 inches

Difficulty: Easy-Moderate

Minimum Tank Size: 20 gallons

24. German Blue Ram

The lesser-known German Blue Rams, also called the Butterfly Cichlids, are interesting freshwater Cichlids that are perfect for community tanks.

They might not be among the most popular aquarium fishes, but their bright colors could be everything you need to build a one-of-a-kind aquarium at home.

Their bright yellow bodies will always get all the attention inside the tank and might even steal your heart at first glance. 

For a small freshwater fish measuring just about 2 inches long, much can’t be said about German Blue Rams’ body sizes. But if the profile of your dream pet fish involves a small, peaceful Cichlid with simple care requirements, the Electric Blue Rams might be the answer.

Size: 3 inches

Difficulty: Moderate

Minimum Tank Size: 10 gallons

25. Gold Barb

And now, to complete our list, who else, if not the dazzling Gold Barbs? They are small freshwater fish that have been famously called the Chinese Barbs.

Gold Barb Fish.

Gold Barbs are endemic to the Red River Basin, covering Vietnam, China, and Taiwan. They are naturally green-colored, but the most common variety in the aquarium trade takes on an exciting gold coloring due to selective breeding.

With their less demanding nature, Gold Barbs should be easy to care for, starting with the ideal tank setup, best possible tank mates, and a balanced diet. They are a peaceful species and should get along with equally friendly fish.

Size: 3 inches

Difficulty: Easy

Minimum Tank Size: 20 gallons

Final Thoughts

So, which is the best small fish for your aquarium? Is it beautiful Barb fish? The agile Mollies? Or maybe classic Platyfish?

There’s something about the nano fish that makes them such a fascinating species in home aquariums.

And if you’ve read our guide to the end, you shouldn’t have any problem picking the best fish for planted aquarium. Of course, everything depends on availability, affordability, and personal interest.

So, if you still need help making the right selection, drop us a short message anytime.