freshwater fish for nano aquarium

Top 12 Small Freshwater Fish for Nano Aquariums – Updated 2020

Petting a small freshwater fish within a nano-aquarium has its own perks. Firstly, you can enjoy the same experience as keeping a big fish. Moreover, they are easy to handle and create very little mess. Above all, it is an ultimate experience as it is entertaining and enjoyable.

There are certain small freshwater fish that are not more than 1-2 inches in size and can easily survive in a 10-gallon aquarium. It’s quite beneficial for beginners as they can achieve experience as well as entertainment.

Additionally, a small aquarium is cost-friendly and affordable as well. Especially for kids, it is an amazing treat and fun too. Although, a small aquarium is easy to set-up, there are still certain valuable things that you should remember.

Here is a complete list of options that you can choose from according to your taste. 15 small freshwater fish for a nano aquarium, here they come.

Let’s get started with them one by one.

Complete List of Small Freshwater Fish for Nano Aquariums

1. Harlequin Rasboras

Scientific nameTrigonostigma heteromorpha
size1-2 inches
Tank size10-gallon max
Care levelEasy
Water temperature72-81-degree Fahrenheit
water pH6.0-7.8
Life span5-7 years
Harlequin Rasbora Table

This amazing freshwater fish is the best choice for a small aquarium. Harlequin rasboras originally belong to South America, Thailand and Singapore. This fish is middle to surface dwellers. They prefer shady and slow-moving water areas.

Harlequin rasboras are a treat to the eyes, they have sparkling silver hue and orange-red fins. Moreover, their signature appearance is their metallic black triangular patch at the rear part of their bodies. They are different from the rest of rasboras so they are called heteromorpha.

This small delicate fish is peaceful and calm, it gets well along with its tank mates. Harlequins are easy to take care of and their diet is quite simple. They can feed on bloodworms, pellets, flakes and brine shrimps.

Above all, this fish is intelligent, entertaining and fun-loving. They can easily cheer up the whole aquarium. If you set up live plants in an aquarium, then they love to hide and seek. One interesting thing about harlequins is that the male dances and trembles to entice its partner for breeding.

To know more about harlequin rasboras, check out our article on harlequin rasboras here

2. Bettas

Scientific nameBetta splendens
Size3 inches
Tank size2-5 gallon
Care levelEasy to medium
BehaviorCalm (except for other bettas)
Water temperature75-86-degree Fahrenheit
Life span3-5 years
Betta fish Specifications

Bettas are famous for their captivating beauty and marvellous colors. This fish is available in a wide range of colors and types. Bettas are known as Siamese fighting fish considering their aggressive behavior. While keeping a betta in a small fish tank try to put them alone, don’t include other bettas.

Bettas are inhabitants of Basins of Thailand, Cambodia and Vietnam. Betta fish is a close relative of Gouramis. They love to stay alone, but usually enjoy the company of live plants including java moss, Anubis and cherry moss. Favourite tank mates of betta are Tetras, Cory catfish and Danios.

Bettas have a vast range of types based on their colors, tail shapes and patterns. Some of them are following.

  • Marble betta
  • Dragon scale betta
  • Black orchid betta
  • Red betta
  • Spade tail betta
  • Rose tail betta
  • Elephant ear betta
  • Veil tail betta

Bettas have incredibly simple diet constituting fish pellets, flakes and blood worms. Bettas are remarkably intelligent; they can learn several tricks in a small time. Moreover, they have more than 60 morphologies.

Bettas are the number one choice for nano-tanks as they are smart, attractive and fun-loving.

To know more about Betta, check out our article on Betta here

3. Cory catfish

Scientific nameCorydoras Geoffroy
Size1-2.5 inches
Tank size10 gallons
Care levelEasy
Water temperature72-79 degrees Fahrenheit
Life span4-5 years
cory catfish Specifications

If you are looking for a small, pleasant and peaceful fish for your small home aquarium then cory catfish is without a doubt the best choice. These are easy to take care of and are quite hardy. Corys are incredibly social creatures.

Cory catfish are also known as Cory cats or Corydoras. They are associated as armored fish based on its plates of bone-like material running all along the length of their bodies. There is a wide variety of catfish available these days, including salt and pepper catfish and bronze cory catfish.

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They can grow to a maximum of 1-2.5 inches. Cory catfish don’t require much space, as they are bottom dwellers. Their food is pretty simple that mainly contains pellets, bottom feeder tablets, flakes and shrimps. They love to dig around and look for the food.

Corys are nice and friendly. They get quite easily with other tank mates. Catfish usually enjoy the company of shrimps and avoid Cichlids and Jack dempseys. Although, Cory catfish is fairly hardy but they can’t survive poor water conditions.

4. Guppy

Scientific namePoecilia reticulata
Size1-1.5 inches
Tank size4-5-gallon tank
Care levelEasy
Water temperature78-82-degree Fahrenheit
Life span1.5-2 years
Guppy Specifications

Another interesting freshwater fish for nano-tank is a guppy. They can rapidly boost up the aesthetics of your aquarium. Perfect for beginners, kids and those who don’t want large mess must have this fish.

Their natural habitat is around northeast South America. Guppies are available in every imaginable color. They are also known as million fish and rainbow fish. Guppy fish beautiful metallic lustrous bodies with many colors around their bodies.

There are more than 300 different types of guppies, some of them are mentioned below.

  • Cobra guppy
  • Snakeskin guppy
  • Grass guppy
  • Mosaic guppy
  • Leopard guppy
  • Spear tail guppy
  • Swordtail guppy

Care Guide

To provide an environment close to their natural habitat, you must focus on maintaining water parameters. Especially, guppies are warm water fish so their tank must be equipped with a water heater. Clean and fresh water is a basic necessity for survival and growth of this fish.

When it comes to their food, they love to eat mosquito larvae. While keeping them in captivity they can eat any random fish food or pellets. Guppies are not picky-eaters so simple diets go well with them.

Guppies are peace-loving and friendly. They manage to get along with most of the freshwater fish including Mollies, Gouramis and Corydoras. Redtail sharks and barbs should be kept away from them as they tend to harm guppies.

5. Platies

Scientific nameXiphophorus maculatus
Size2-3 inches
Tank size10-gallon max
Care levelEasy to moderate
Water temperature70-75 degrees Fahrenheit
Life span3-5 years
Platies Specifications

This fish was first introduced in 1907 around the freshwater of Mexico. It is one of the favourite fish of fish hobbyists. Platies have many different types based on their habitat, tail shape and colors. Some of these types are following.

  • Southern platy
  • Variable platy
  • Swordtail platy
  • Spiketail platy

Platies are calm and serene creatures. They are remarkably active and quite entertaining as well. Platies usually get along well with their tank mates as well as their owner. Sometimes, the male one like to jump out of the tank when excited.

Platies have wonderful colors and amazing patterns. Their tail shape is also mesmerizing. Platies have a wide range of colors including, yellow, orange, red, black, blue, green and white depending upon their habitat.

 Although, platies are quite hardy there are certain tips to remember before setting up their tank. Clean the tank every 2 weeks, change almost 25% of the water every time. To maintain the tank set up close to the natural environment, use a planted tank or gravel-based tank.

Platies are not very picky-eaters, they prefer a plant-based diet. Moreover, worms, shrimps, crustaceans, and insects are a good option for food. Minerals and vitamins are necessary for flourishing their color.

6. White cloud mountain minnow

Scientific nameTanichthys micagemmae
Size1-1.5 inches
Tank size10 gallons
Care levelEasy to moderate
BehaviorPeaceful and social
Water temperature60-65-degree Fahrenheit
Life span3-5 years
Mountain Minnow Specifications

White cloud minnows are small, delicate and colorful creatures. This fish was first discovered around 2001 in china and Vietnam. They are commonly known as canton minnow, Chinese minnow and white cloud. Moreover, regarding their close connection to neon tetra white cloud is referred to as the working man’s neon.

Minnows are basically top or middle dwellers. Their males are more colorful and charismatic as compared to females. Furthermore, males are slenderer looking, while, females are chubby looking. Their lower jaw is slightly protruded.


Cloud minnows have a sparkling brown-bronze body with a ray of fluorescent running alongside from eyes to tail. Rest of their body is white in color and the fins are dazzled with orange-red color.

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When setting up a comfortable living space for white cloud minnows focus on maintaining an appropriate temperature. They can’t survive in water temperature under 72-degree Fahrenheit. Try fixing up a large number of live plants and rocks to establish the natural environment.

White cloud minnows can feed on any small thing available. Naturally, they are insect eaters, feeding on mosquitoes and other insect larvae. Minnows also gladly appreciate live or frozen worms or pellets and flakes as well.

Minnows are friendly and calm creatures. They appreciate a good company. Avoid placing them with bigger fish as they might get eaten.

7. Glow light Tetra

Scientific nameHemigrammus erythrozonus
Size1-1.5 inches
Tank size10 gallons
Care levelEasy
Water temperature74-82-degree Fahrenheit
Life span5 years
Grow Light Tetra Specifications

Commonly known as fire neon, this fish was first introduced to aquatics in around 1933. Glowlight tetra originally belongs to river waters if south America. If you are looking for some fish that can boost up your fish tank then here it is, Glowlight tetra is an amazing choice.

Glowlight tetras are gorgeous and intelligent creatures. They are fairly easygoing when it comes to care and food. Tetras are peaceful and entertaining. A bunch of these beauties can surely cheer anyone up.


Glowlight tetra is most popular of all tetras. They have pearlescent peach-silver body finely divided by a glowing red-golden stripe. When seen from far apart they look like a glowing bulb.  Edges of their dorsal fin are same red-golden while that of anal and pelvis fin is white.

Glowlight tetras are quite undemanding when it comes to tank conditions. They prefer a darker environment with enormous plants and rocks. Being omnivorous in nature, Glowlight tetra readily accepts frozen or dried food, fish pellets and flakes.

Glowlight tetra enjoys the company of other tetras as well as Barbs, Catfish and Danios. One fish to avoid will be angelfish, as angelfish get attracted to its colors and can make a good meal out of it.

8. Killifish

Scientific nameNothobranchius rachovii, 
Size1-2 inches
Tank size10-gallon
Care levelEasy to moderate
BehaviorPeaceful and calm
Water temperature72-75-degree Fahrenheit
Life span3 months-5 years
Killi Fish Specifications

Keeping a killifish can prove rewarding and enjoyable. This is one of the most diverse groups of fish. Killifish have different modes of living depending upon different species of them. Some of them are easy to keep and some are quite hard, some belong to tropical and some of them belong to subtropical regions.

One thing that is worth admiring is their mesmerizing beauty and stunning patterns. They usually have round scales and their body is pike shaped. Their appearance also varies in different species.

Males are much brighter in colors and way much aggressive than their counterpart. Thus, avoid keeping two males in the same tank. Females are calm and friendly thus get along well with each other as well as with other fish.


Killifish size also varies from specie to specie, mostly they are 1-2 inches but some of them might grow up to 5 inches. A killifish is a perfect option for small fish tanks.

Killifish is remarkably hardy and can easily handle fluctuating water conditions. They generally prefer dark water environment. Changes in pH and temperature usually are well survived.

Killifish is not a fussy-eater. Most of their diet consists of insects, crustaceans, worms and mosquito larvae. Some of them also eat algae. Best food of adult is daphnia, shrimps and bloodworm.

9. Bumblebee Goby

Scientific nameBrachygobius xanthozonus
Size1-1.7 inches
Tank size10 gallons
Care levelModerate
Water temperature73-79-degree Fahrenheit
Life span4 years
Bumblebee Goby Specifications

These small freshwater fish got its name from their appearance that resembles the common bee. Bumblebee is quite small with an adult having a maximum size of 1.7 inches. They belong to family Oxudercidae.

Bumblebee goby is generally black in color, with pale yellow-orange bands all over them.

Males are generally more vibrant and slimmer. Males have more orange bands. Bumblebee goby is very shy and peaceful specie but it’s definitely not for beginners as its need are difficult to fulfill.

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Bumblebee goby is remarkably active and energetic. They love to swim so require plenty of open space. Their living space must have plenty of rocks, sand bottom and live plants.

Bumblebee goby is a schooling fish so I would recommend that you keep at least 5-6 of them together.

 10. Dwarf Puffer

Scientific nameCarinotetraodon travancoricus)
Size1-1.5 inches
Tank size5-gallon
Care levelEasy
Water temperature77-79-degree Fahrenheit
Life span4 years
Dwarf Puffer Specifications

This intelligent and cute little fish is another perfect addition to your aquarium. Dwarf puffer is also commonly known as pea puffer displaying its small size. Dwarf puffer is surprisingly hardy regarding their size and can live up to 4 years.

Male of this community can be a little aggressive and competitive, whereas females are peaceful and calm. Thus, avoid keeping two males in the same aquarium otherwise it can be a mess.

Commonly seen dwarf puffer is usually dark green and have black blotches over their body. Regarding shape, both male and female have round bodies that narrow toward the tail. Puffers have exceptionally large eyes for their small body.


Dwarf puffer originally came from rivers and lakes of southwest India. Dwarf puffers are quite undemanding in terms of ideal water conditions. They require a maximum of 12 hours of sunlight. Whereas, pH and temperature usually don’t affect them much.

Dwarf puffers are fairly simple in terms of diet. They can be fed on anything including, insect larvae, algae, shrimps, snails, bloodworms and water fleas. Feeding them twice a day will be enough.

In a natural environment, dwarf puffers enjoy the company of barbs, paral fish, Malabar leaf fish and orange chromide. In captivity, they can get along well with ember tetra, zebra danio, harlequin rasbora and other algae eaters.

11. Celestial Pearl Danio

Scientific name Danio margaritatus
SizeMax 1 inch
Tank size10 gallons
Care levelMedium
Water temperature73-79-degree Fahrenheit
Life span3-5 years
Pearl Danio Specifications

This amazing fish got its name from pearl-like spots on its body. A local inhabitant of south-east Asia, this fish caught the eye of aquatics within a blink of an eye. Celestial pearl danios are very small in size and quite shy in nature, so they get along well with guppies and mollies.

One basic element of their environment is live plants. To mimic their natural habitat, you must provide a fair number of plants in the tank and that will make the danios happy and cheered. They adapt their color from their surrounding plants and colorful fish.


Celestial pearl danios have Magnificient appearance constituting white pearlescent spots all over them combined with red-orange colored fins and tail. Moreover, their fins have parallel black colored lines. Males are more vibrant in color as compared to females.

A dark substrate, plenty of plants, rocks and caves make a perfect living space for these danios. There is quite a margin in water conditions referring to their hardy nature. They require moderate to low lightening.

Most of their diet consists of plants, algae and zooplankton. But regarding their omnivores nature, they can also eat worms, insects and invertebrates. Celestial pearl danios are egg layers and can lay up to 30 eggs at a time.

12. Neon Tetra

Scientific nameParacheirodon innesi
SizeMax 1.5
Tank size10 gallons
Care levelEasy
Water temperature70-81-degree Fahrenheit
Life span8 years
Neon Tetra Specifications

When we are on the top of small freshwater fish for nano aquarium we cannot simply eliminate neon tetras. No doubt one of the most popular fish among aquatics, this amazing fish belongs to south America. The neon tetra is an ideal fish for beginners and kids as it is calm and easy to care for.

 Moreover, their diet is quite simple and they are entertaining and energetic. Above all their limitless beauty makes them irresistible to aquatics.


Their color is their characteristic feature. Neon tetra has blue-green color all over with turquoise line running from its eye toward the tail. Furthermore, another thing that adds to their beauty is a sensational red-orange line that runs from the centre of their body toward its tail.

To replicate their natural habitat, warm water is essential. The neon tetra is fairly drawn towards vegetation and dark atmosphere. Dark substrate, enormous plants, soft and warm water with pH between 6-7 are ideal conditions for tetras.

Neon tetras are omnivores, so they feed both on plants and meat. Bloodworm, shrimps, daphnia and insect larvae are suitable for their diet. Furthermore, you can also feed them on flakes, dried or frozen food. Algae and other plant material are highly appreciated.

Neon tetras are timid and peaceful in nature, they usually get along well with most of their tankmates. They enjoy the company of dwarf cichlids, small catfish and barbs. Bettas, angelfish ad large cichlids should be avoided.

Bounus Fish

13. Endler’s Livebearers

Scientific namePoecilia wingei
SizeMax 1.8 inches
Tank size10 gallons
Care levelEasy
Water temperature66-84-degree Fahrenheit
Life span2-3 years
Endlers Livebearers Specifications

This small freshwater fish is currently an endangered species, some also claim that they are extinct. Endler’s livebearers are beautiful, smart and intelligent. Their natural habitat is loaded with vegetation. Endler’s livebearers are close relatives of guppies, but they are quite rare now.


They prefer a dark environment with plenty of vegetation and warm water. Females can grow up to 1.8 inches but males hardly reach 1 inch in length.

They have sensational vibrant colors. Their bodies reflect every color possible. Their mesmerizing beauty makes the aquatics fall in love with this fish immediately. They can effectively manage in small space.

Breeding is quite troublesome for these beauties as they get weakened and die shortly after giving birth. Endler’s livebearers are quite hardy and perfect for beginners. Their males are peaceful and calm whereas the females can sometimes get aggressive.

These livebearers are surprisingly active and energetic, they can even attempt to jump. So you better keep an eye on them.


This was our list of top 12 Top 12 Small Freshwater Fish for Nano Aquariums and their behaviour, water conditions and care guide.

We hope that we have provided you with enough information so that you can set-up your nano aquarium.

These small freshwater fish are suitable for a minimum of 10 gallons tank.

For more information about other freshwater and saltwater fish click here.

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