25 Best Fish for a 5 Gallon Tank

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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.

5 gallon tank is a small aquarium which can be a important focal point at home. But one of the most obvious questions is always going to be, which are the best fish for a 5-gallon tank?

Do you have an answer just yet? If not, this detailed guide reviews 25 little critters that would do well inside such tanks.

From the ever-popular Guppy fish to the showstopping Bettas, as well as the odd-looking Dracula Minnows, let’s see what makes these little guys quite exceptional inside small tanks.

1. Guppy Fish

Guppies are small fish for a small tank. At only 2.5 inches in maximum length, these South American petite critters can readily survive inside a 5-gallon tank.

Many people look at the Guppy fish’s small body sizes and instantly conclude that they are passive dull pets. But that’s never true. While they deservedly rank among the smallest freshwater fish, Guppies are one of the most active pets you will ever find in the aquarium hobby.

They will constantly want to explore a compact community tank, creating an eye-catching display that you will never see with even the largest of aquarium fish.

Size: 2.4 inches

Difficulty: Easy

2. Betta Fish

Like Guppies, Bettas require a modest tank when kept at home, and that’s down to their small body sizes that never exceed 3 inches in optimal growth.

crowntail betta swimming in tank.

While we could talk endlessly about their beautiful, unique-looking bodies, these tiny Asian critters are even more appealing with their resilience in captivity.

A typical Betta fish is naturally hardy, dwelling in shallow ponds and slow-moving streams with murky waters. But let’s face it. Most Betta fish can be aggressive, willing to pick unnecessary fights with any vulnerable fish species at home.

So, the best way to counter such weaknesses is to restrict the Betta fish to a species-only aquarium.

Don’t keep more than one male Betta fish in the same habitat. And as long as other needs are fully met, you won’t get enough of their alluring jewel-tone coloring and long fins. 

Size: 3 inches

Difficulty: Easy

3. Neon Tetra

Well, you can’t mention a 5-gallon tank without mentioning the eye-catching Neon Tetras. They look like the perfect fish for a 5-gallon tank, and their brightly colored small bodies prove just as much.

Green Neon Tetra swimming in tank.

Beautiful as they are, a typical Neon Tetra fish only needs warm, soft waters with slightly acidic pH to thrive at home. They have a characteristic torpedo-shaped profile with a glittery blue stripe running the length of their bodies.

As a peaceful fish with an easygoing personality, you will have plenty of suitable species to keep with the gorgeous Neon Tetras as long as the tank size guarantees everyone’s comfort.

Size: 1.5 inches

Difficulty: Easy

4. Sparkling Gourami

Sparkling Gouramis are Southeast Asian freshwater fish with straightforward care requirements. They are one of the best options for beginner-level aquarists, and as a 5-gallon tank fish, they will display a striking pattern inside the tank.

sparkling gourami swimming in aquarium.

Much of Sparkling Gourami care involves their typical behavior and activity levels. And as highly active freshwater fish with intricate details all over their bodies, effective Sparkling Gourami care kicks off with proper planning.

Ensure you create the standard Gourami environment with enough vegetation, a darker substrate, and plenty of hiding places to guarantee everyone’s long-term survival.

Size: 1.5 inches

Difficulty: Easy

5. Clown Killifish

Clown Killifish is a small African micro predator fish that’s exciting to have at home. They are one of the best options for populating a nano tank, taking on a torpedo-shaped body profile with black and yellow stripes.

Clown Killifish swimming in fish tank.

The male fish have more vibrant colors and are easily noticeable inside the tank.

While they only measure about 1.4 inches in maximum length, Clown Killifish never shy away from showing their predatory instincts inside the tank. They will hunt insects and other small creatures to get their favorite meaty proteins at any cost.

When kept in captivity, the Clown Killifish appreciate the presence of adequate tank decorations like natural plants, driftwood, and plenty of hiding spots.

Size: 1.4 inches

Difficulty: Easy-Moderate

6. Chili Rasbora

Chili Rasbora is the true definition of a perfect nano fish, adored for its attractive body pattern that creates an instant visual appeal. They measure just about 0.7 inches in full maturity, becoming the clear winners of the smallest aquarium fish tag.

Chili Rasbora swimming in a fish tank

Their brilliantly colored red bodies are visible from any position, with black shades that create a contrasting effect inside the tank. Chili Rasboras appreciate plant tannins inside the tank to create an acidic environment they are quite fond of in the wild.

For a dream 5-gallon tank fish that has it all, don’t go further than the lovely Chili Rasboras.

Size: 0.7 inches

Difficulty: Easy

7. Endler’s Livebearer

Well, it was only a matter of time before Endler’s Livebearers became everyone’s favorite live-bearing fish of the Poeciliidae family. For many aquarists, there’s no difference between these beautiful species and the ever-popular Molly fish and Guppy varieties.

Endler’s livebearers swimming in the tank

And while we tend to agree with them, we find Endler’s Livebearers even more special with their limited distribution in the aquatic scene.

They originate from Laguna de Patos in Venezuela, and with vibrant shades of neon coloring, it’s hard not to include them inside your tank. Besides, they have simple care requirements at home and can easily mingle with most fish species inside a large tank.

As a small nano fish, you will want to pay more attention to the water parameters and the fish’s dietary needs to ensure they are well suited to their new home.

Size: 1.8 inches

Difficulty: Easy

8. Dwarf Pea Puffer

Dwarf Pea Puffer, also called the Pygmy Pufferfish, is the world’s smallest pufferfish, perfect for small nano tanks. They are an odd-looking species you can keep to introduce some variety inside the tank.

Dwarf Pea Puffer swimming in tank.

Their impressive maneuverability tactics, coupled with high activity levels, make them an incredible inclusion to modern aquariums.

While they struggle to reach a standard 2-inch length at home, Dwarf Pea Puffers are excellent swimmers, with a constant darting movement that’s sure to capture your attention no matter the tank size.

As for the typical appearance, Dwarf Pea Puffers have bright yellow base coloration with green, black, gold, and brown shades on their backs. Their small fins complemented with the large, protruding eyes make them the little wonder of the aquarium hobby.

Size: 1.5 inches

Difficulty: Moderate

9. White Cloud Mountain Minnow

White Cloud Mountain Minnows are named after their original habitat, the White Cloud Mountain in Guangzhou, China. They fit the category of perfect small aquarium fish, with 2 inch long bodies packed with matchless beauty.

White Cloud Mountain Minnow

For many years, aquarists have compared White Cloud Mountain Minnows to the lovely Neon Tetras thanks to the general body appearance. And it’s hard to spot many differences between the two species.

However, White Cloud Mountain Minnows have the added advantage of being less expensive, readily elevating the tank’s appearance without breaking the bank.

Like the natural environment, white Cloud Mountain Minnows prefer clear waters in cooler conditions with enough vegetation.

Size: 1.5 inches

Difficulty: Easy-Moderate

10. Harlequin Rasbora

Ever since they were first introduced to the aquarium hobby, Harlequin Rasboras have become one of the best fish for 5 gallon tank. And that’s partly due to their small, diamond-shaped bodies and partly because of their hardiness.

Even with their small sizes, Harlequin Rasboras still understand what it takes to attract attention with their eye-catching bodies, sometimes likened to a lovely work of art.

A typical Harlequin Rasbora is nothing if not showstopping, wearing a dramatic reddish-orange and black coloring that’s sure to turn a couple of heads. 

As a small, peaceful fish for a small tank, the Harlequin Rasboras know nothing about aggression. They prefer a peaceful community and will have their best lives in blackwater habitats.

Size: 2 inches

Difficulty: Easy

11. Least Killifish

Hailing from the still water bodies of North America, Least Killifish is another fascinating freshwater fish that can easily thrive inside a 5 gallon tank.

Least killifish swimming in an aquarium.

They tolerate tougher conditions than most fish species usually do, which prepares them for any possible eventuality in captivity.

The least Killifish will be the most noticeable when kept with the right tank mates, with their flat bodies and olive coloring standing out inside the aquarium.

As one of the smallest live-bearing fish in the world, don’t be afraid to introduce the Least Killifish to a 5-gallon tank.

But when doing so, be sure to set clear boundaries with enough hiding places because these little guys will always want to mind their own business.

Size: 1.4 inches

Difficulty: Moderate

12. Galaxy Rasbora

They are called the Galaxy Rasboras for a good reason, and if their sparkly deep blue coloring doesn’t capture your attention, probably nothing ever will.

Celestial Pearl Danio

Celestial Pearl Danios are an exceptional fish species originating from the small, shallow ponds of Myanmar.

They have deep red or orange fins with a tall, colorful dorsal fin that perfectly balances their bodies when swimming.

As beautiful as they are, one only wonders if the Galaxy Rasboras are truly made for a 5 gallon fish tank.

Well, to set the record straight, a bigger tank is always better for any fish species. However, a beautiful 5-gallon aquarium can still do the job as long as you maintain the parameters within the acceptable range.

For the attractive Celestial Pearl Danios, a constant supply of high-quality fish food is crucial to a long lifespan by eliminating stress and common freshwater fish diseases.

Size: 1 inch

Difficulty: Moderate

13. Pygmy Corydoras

If you thought the Corydora fish weren’t ideal for small 5 gallon tanks, perhaps you haven’t seen the Pygmy varieties. These are a smaller variety of the standard Corydora fish known to coexist with several peaceful tank mates.

 Pygmy Corydoras swimming in an aquarium.

Typically, Pygmy Corydoras are endemic to Brazil’s Madeira River Basin’s tropical waters, where they enjoy specific water conditions.

At only 1 inch long in maximum size, the Pygmy Corydoras need a natural-looking habitat, with plenty of plants and driftwood for added protection.

With a beautiful thick black band running vertically on their bodies, Pygmy Corydoras are much more than just a hardy species. And you won’t have better options where beauty and resilience inside a 5-gallon tank matter most.

Size: 1 inch

Difficulty: Easy

14. Scarlet Badis

A micro predator that’s a little obsessed with eating worms and insect larvae, Scarlet Badies have no problem living inside a moderately cramped aquarium. They get plenty of attention as the perfect nano fish, and it’s easy to see why.

Scarlet Badi swimming in tank.

Scarlet Badis are gentle creatures that only want to maximize their time inside the tank. That’s why they need maximum protection from large, predatory fish that may want to feast on them.

Keeping these fish inside a small, 5-gallon tank will help them stand out, as they make every deliberate attempt to capture your attention.

With a lovely red or orange coloring in the male Scarlet Badis, it would seem the small sizes haven’t taken anything away from these fish’s natural beauty.

Furthermore, they will have vertical stripes extending all over their bodies. On the other hand, the female fish will have an orange-gray coloring that’s just as addictive to look at.

Size: 0.8 inches

Difficulty: Moderate

15. Honey Gourami

If it’s all about introducing variety inside a 5-gallon tank, how about switching from the monotony of the standard Gourami fish? Honey gourami is a gorgeous freshwater aquarium fish that’s so peaceful yet adorable.

honey gourami swimming in a tank

They are called Honey Gouramis because they break away from the simplicity of the standard Gourami fish.

That being said, the adult Honey Gouramis have a light orange-yellow coloring that will always capture your attention no matter the size of the chosen tank mates.

Conversely, the female fish are just as captivating, taking on a silvery coloration with light gray fins. Both species have slim bodies typical of most Gourami fish, and they are more secure in shoals.

Size: 2 inches

Difficulty: Moderate-Advanced

16. Molly Fish

Molly fish, also called the Common Molly or Short-finned Molly, is a staple name in the aquarium hobby, revered for its ease of care and adaptability in captive environments.

molly fish

They originate from Colombia and Mexico’s coastal marine waters and freshwater streams as a self-sufficient species that only wants to play, explore, and swim.

They have a flat profile with triangular heads and bodies tapering towards the tail. Unlike most species, Molly fish are easy to breed at home, rapidly increasing their tank population with quality care.

A major aspect of their care involves water parameters. And as long as everything stays within the acceptable range, the Molly fish won’t have any problem living inside tanks as small as 5 gallons.

Size: 4-4.5 inches

Difficulty: Moderate

17. Ember Tetra

Ember Tetras are another perfect addition to small aquariums. Why? Because they are small, peaceful, and beautiful.

ember tetra swimming in aquarium

If you need a 1-inch long fish species that tickles all boxes, we confidently recommend these Tetras.

The major selling point of Ember Tetras is their colorful appearance. They spot an attractive bright orange coloring that makes them a standout option for nano aquariums.

On top of that, the Ember Tetras have a tall dorsal fin, with forked caudal fins and the Tetra-like appearance that’s so adorable in the aquarium hobby.

Their typical behavior and activity level predict their health in captivity. An agile Tetra indicates good health, just like a dull Ember Tetra shows that it’s not well fed.

Size: 0.8 inches

Difficulty: Easy

18. Amano Shrimp

Now, this is not a freshwater fish but a fun, little creature perfect for a small aquarium. A typical Amano Shrimp is beautiful to watch, even more so during feeding, as they desperately race after their favorite meal. 

amano shrimp in an aquarium.

Amano Shrimps are predominantly found in Japan and Taiwan and only reach 2 inches long in full length. They have have transparent, gray bodies with red-gray or blue-gray dots all over their bodies.

Amano Shrimps are fun to have at home, whether in a species-only tank or as part of a peaceful community, with their tranquil disposition always assuring that they will have an endless list of potential tank mates at any given time.

Of course, larger groups will need a larger aquarium. But if it’s a small community, they will happily thrive inside a smaller tank.

Size: 2 inches

Difficulty: Easy

19. Cherry Shrimp

If it’s time to switch from the monotony of freshwater aquarium fish, you won’t have better options than Cherry Shrimp.

Cherry Shrimp in aquarium.

Cherry Shrimp is one of the most sought-after invertebrates of the Atyidae family that comes in clutch when setting up a small, 5-gallon tank.

Such is their increased value in the aquarium trade that aquarists now grade the Cherry Shrimps according to body coloration.

If it’s intense red, it will have the highest value in the pet market. Conversely, a dull Cherry Shrimp with red patches is less valuable in the aquarium community, costing the least amount in the local market.

The best part? Cherry Shrimps need a modest tank if kept at home. In many cases, a 5-10 gallon tank should do the trick as long as you provide high-quality food and enough vegetation for added protection.

Size: 1.5 inches

Difficulty: Easy

20. Dwarf Crayfish

For some people, Cherry Shrimp or Amano Shrimp is simply not their thing.  

If you are one of those, you will need the perfect alternative to add an interesting look to the tank while mingling with just about any species. The best part? They can do so without requiring a ton of space.

dwarf crayfish

Dwarf Crayfish seem to tickle all boxes, resembling the typical lobsters in many ways yet peaceful and active at the same time.

With a 2 inch maximum length, setting up a Dwarf Crayfish’s habitat shouldn’t pose any challenges. But remember to include enough plants, driftwood, rocks, and other important hiding spots.

Size: 1.6-2 inches

Difficulty: Easy

21. Nerite Snail

Nerite Snail is a lovely little critter perfect for smaller aquariums. They are known for their tank cleaning abilities and a discreet appearance that often complements the tank display.

Nerite Snail swimming in tank.

At only one inch long in maximum size, these amazing little critters will always want to latch onto the tank surfaces at any given time, spending maximum time clearing any unwanted algal growth inside the tank.

Anyone who introduces Nerite Snail to their home aquariums doesn’t have to worry about dietary requirements because these little snails can readily scarf down huge amounts of algae down their throats.

Again, with their small sizes, it’s a no-brainer Nerite Snails will happily mingle with any peaceful aquarium fish like the Barbs, Tetras, and Guppies.

While you will spot multiple color variations in a Nerite Snail family, the typical beautiful varieties with yellow-black shells are the most common.

Size: 1 inch

Difficulty: Easy

22. Rosy Loach

Rosy Loach is a social, nano-sized freshwater fish of Asian descent. They belong to the Botia family as beautiful, friendly fish that readily thrives in small tanks.

Rosy Loach swimming in tank.

When introduced in home aquariums, the first step to effective Rosy Loach care will be to keep them in groups as that alone makes them healthier and more secure.

On top of that, Rosy Loaches prefer slow-moving waters with plenty of hiding places and vegetation that replicates the actual conditions in the wild.

Also, these fish species rely on their delicate barbels when feeding, meaning you must only consider a soft, sandy substrate at the tank bottom.

Size: 1 inch

Difficulty: Easy

23. Asian Stone Catfish

The Asian Stone Catfish, sometimes called the Anchor Catfish, is a peaceful freshwater fish comparable to most nano fish in terms of ease of care.

Asian Stone Catfish swimming in tank.

They originate from the slow-flowing streams of Bangladesh and India as a low-maintenance species that only measures about 1.4 inches in full length.

As far as its temperament goes, Asian Stone Catfish tends to be peaceful and shy, yet so charming at the same time with a feeding plan that encompasses most freshwater fish food. They thrive with a fine sandy substrate, dim lighting, and enough hiding places.

If you need a freshwater fish that can thrive in cold water conditions (usually 64.4°F-75.2°F), with acidic to neutral pH (5.6-7.6), Asian Stone Catfish is worth every penny. Of course, don’t forget to keep them in groups to guarantee their safety inside the tank.

Size: 1.2-1.4 inches

Difficulty: Easy

24. Dracula Minnow

Dracula Minnow is another small fish for a small aquarium. They are active swimmers, growing up to 0.65 inches in full length, and readily bringing any aquarium to life.

Dracula Minnow swimming in tank.

Generally, Dracula Minnows prefer slightly acidic to alkaline waters (6.5-7.5) when introduced to community tanks and thrive in cooler conditions (66°F-78.8°F).

They are rightfully called Draculas because of the intimidatingly protruding bones just next to their jaws. However, these little minnows are peaceful community fish ready to mingle with equally friendly species in the same tank.

Feeding them on high-quality micro foods like daphnia and worms is important to maintain their spotless appearance in captivity.

Size: 0.6 inches

Difficulty: Easy

25. Red Neon Blue-Eye Rainbowfish

Red Neon Blue-Eye Rainbowfish is a lesser-known variety of the Blue Eye Rainbowfish endemic to Indonesia and Papua New Guinea. It is happier with its kinds in large schooling communities and is an outstanding fish for a 5 gallon tank. 

Red Neon Blue-Eye Rainbowfish swimming in the tank

Typically, the male fish has a stunning look, sporting a beautiful neon red-red orange and blue coloring that’s easily noticeable inside the tank.

They are less demanding fish with a friendly personality that allows them to coexist with other peaceful fish of the same size.

As with most Rainbowfish varieties, the Red Neon Blue Eye Rainbowfish readily shines when kept in groups of half a dozen fish or even more with a fine, dark substrate.

Size: 1.2-1.5 inches

Difficulty: Easy-Moderate

Final Thoughts

So, what fish are good for a 5 gallon tank? 

Small fish for small tanks are probably the most underrated species in the aquarium hobby. And as you can see, the tank size doesn’t matter if you get the right species and include proper decorative elements.

The 25 species on our list are rewarding to have at home, less demanding at all times yet so adorable and highly adaptable inside the tank.

Whatever species you choose, we hope it will make your fishkeeping hobby even more enjoyable.