The Freshwater Fish Hub

Freshwater fish come in all kinds of colors, shapes and sizes and every type of freshwater fish has different needs. The Freshwater Fish Hub is your introduction to the wonderful world of keeping freshwater fish as pets.

What are freshwater fish?

Freshwater fish are species of fish that live in water with very low salt levels. Unlike saltwater fish – which live in the salty oceans and seas – freshwater fish live in ponds & lakes, streams & rivers, and wetlands. These bodies of water contain very low amounts of salt and freshwater fish are specially adapted to live in these low-salt environments.

What fish can live in fresh water?

Freshwater fish could not survive in saltwater and saltwater fish could not survive in freshwater. Understanding the difference between freshwater and saltwater fish is therefore very important.

There are over 10,000 species of fish that can live in fresh water. In fact, over 40% of all fish species live in these fresh water habitats. That’s a remarkably high number when you consider that fresh water makes up just 3% of the water on Earth.

The other 60% of fish species are saltwater fish. They live in the world’s oceans, which between them hold 97% of the water on Earth.

Only fish with specially adapted physiologies can live in fresh water. The scales of freshwater fish help to stop them from losing salt through their skin, while their kidneys reclaim salts from their waste before it is excreted from the body.

What fish can go in a freshwater tank?

There may be tens of thousands of freshwater fish species, but not all types of freshwater fish are suitable for the home aquarium.

Some freshwater fish simply grow too large for a fish tank, while others need conditions that are difficult or impossible to replicate at home.

Fish that can go in a freshwater tank are usually smaller varieties that have been bred for the pet trade.

When choosing freshwater fish for your tank, you need to think about what size tank you have and the specific needs of your chosen fish species, as well as their compatibility with other fish they may be sharing the tank with.

Below, we list 21 popular examples of freshwater fish for you to consider.

A fantail goldfish opening its mouth
Goldfish are the most popular type of pet freshwater fish, though they’re often poorly cared for and kept in tanks that are too small.

iStock.com/MirekKijewski

Freshwater fish examples

A list of freshwater fish species that are often kept as pets. Explore 21 popular types of freshwater fish, with pictures.

Angelfish

Two angelfish in a freshwater fish tank
One of the most popular freshwater fish to keep as pets. But beware of how big they can grow! Angelfish can reach 6 inches tall, so need a large, deep tank.

iStock.com/panida wijitpanya

Barbs

A rosy barb in a freshwater aquarium
A colorful, energetic fish that should be kept in a school (group of fish) of five or more. Barbs come in a wide variety of colors and sizes.

iStock.com/Mirko_Rosenau

Bettas

A blue and red betta fish with its distinctive long flowing fins
Also known as the Siamese Fighting Fish, male bettas are highly territorial. Keep alone in a decorated tank with lots of hiding places.

iStock.com/NatalyaAksenova

Kenyi Cichlids

A kenyi cichlid with silver and black zebra markings
Also known as Maylandia lombardoi, Kenyi Cichlids are an aggressive fish that should be kept in a group of one male and several females. However, they’re big fish, so a lot of tank space would be needed.

iStock.com/Mirko_Rosenau

Corydoras Catfish

A corydoras catfish lying on gravel at the base of a freshwater fish tank
A peaceful fish that will add interest to the bottom of a tank – as well as helping to keep it clean. Corys should always be kept in groups, where they will exhibit schooling behavior, never alone.

iStock.com/Przemysław Iciak

Danios

A pair of celestial pearl danios in a freshwater aquarium
A wide range of Danio species are available to choose from. All are hardy, energetic fish that do well in cooler water. Sizes vary by species, but some can reach approximately 5 inches in length.

iStock.com/corridor91

Discus

A brightly colored discus fish
Native to the Amazon river basin, Discus are easily recognizable due to their flat disc-shaped bodies. A single discus needs a large tank of 50 gallons or more.

iStock.com/sergeyskleznev

Goldfish

A fantail goldfish opening its mouth
One of the most popular pets in the world. The biggest mistake people make with goldfish is not realising how big they grow. They need a large tank – not a small bowl

iStock.com/MirekKijewski

Gouramis

A pearl gourami on a dark background
Gouramis come in a wide variety of small to medium sized varieties. Dwarf Gouramis are particularly popular among freshwater fish-keepers and are easy to care for.

iStock.com/wrangel

Guppies

A male guppy with an orange-red tail with black spots
Guppies are easily recognized by the male’s brilliant colorful tail. Guppies breed very easily, which makes them perfect for attempting to breed fish with your choice of colors and patterns.

iStock.com/subinpumsom

Hatchets

A silver hatchet fish
A great community fish with a surprising party trick… Hatchet fish can jump several meters! To avoid your fish jumping out of the water, try not to startle them and make sure your tank has a tight lid!

iStockcom/Besjunior

Killifish

A lyretail killifish with red spots and yellow fin tips
Not commonly found in pet stores, killifish are a little overlooked. This is despite the fact they are small, colorful fish ideally suited to the home aquarium, with over 1000 species available.

iStock.com/Mirko_Rosenau

Loaches

A clown loach looking for food on a rock in a freshwater fish tank
An alternative to catfish, loaches also live at the bottom of the tank and scavenge for food amongst the substrate. This makes them a great choice for keeping your tank free of debris!

iStock.com/Juan Carlos Juarez Jaramillo

Mollies

A black molly freshwater fish on a light background
Like guppies, mollies are live-bearers, which means they give birth to live young rather than laying eggs. They are larger and more delicate than guppies so need lots of room and good care.

iStock.com/Mirko_Rosenau

Platies

A platy with an orange body and dark fins
Another live-bearer, platies are very easy to breed. Get a small group of male and female platies and you will soon have a packed tank. Or you could try breeding your own shapes and color varieties.

iStock.com/Juan Carlos Juarez Jaramillo

Plecostomus

A bristlenose pleco, also known as a plecostomus, resting at the bottom of a freshwater fish tank
Also known as the suckermouth catfish, plecos (as they’re commonly called) are algae-eaters that attach themselves to surfaces using their mouths. They grow very large so need a lot of tank space.

iStock.com/Mirko_Rosenau

Rainbowfish

A dwarf rainbowfish in a freshwater fish tank
Peaceful and active, rainbowfish make great additions to a community tank. The male rainbowfish are at their most colorful when they are trying to attract the attention of females.

iStock.com/NERYX

Rasboras

A rasbora, one of the most popular types of freshwater fish
A name used to describe a wide variety of fish species, rasboras tend to be small, brightly-colored shoaling fish. They’re a great choice if you want to create a nano-tank, which is a very small aquarium.

iStock.com/Mirko_Rosenau

Roseline Sharks

A roseline "shark" (aka denison barb)
Also known as Denison Barbs, Roseline Sharks are not actually sharks. However, a look at their body shape makes it clear why they get the name.

iStock.com/Juan Carlos Juarez Jaramillo

Swordtails

A swordtail fish with its pointed sword-like tail
Another live-bearer and another fish with a self-explanatory name. Swordtails are easily identified by the long pointed section of their tail fin.

iStock.com/sdbower

Tetras

A school of neon tetras with their distinctive blue and red neon coloring
Tiny, colorful fish that do well in groups of as many individuals as you can safely fit in your tank. They enjoy heavily planted tanks and look great against the foliage.

iStock.com/Raghu_Ramaswamy

What is the best type of freshwater fish to have as a pet?

Our top pick for best type of freshwater fish to have as a pet is the Neon Tetra. We can’t think of a better combination of toughness, gentleness, small size, bright color and interesting behavior.

Though there are other options too of course. Any of these pet freshwater fish would make a great beginner choice:

  • Danios
  • Guppies
  • Mollies
  • Platies
  • Tetras

We have 6 key criteria for choosing a great freshwater fish to keep as a pet and these fish tick all the boxes.

A school of neon tetras with their distinctive blue and red neon coloring
Neon Tetras are our top pick for the title of Best Freshwater Fish to Have as a Pet!

iStock.com/Raghu_Ramaswamy

Attributes of good pet freshwater fish

  1. Hardy – Hardy fish can survive a wide range of conditions, which makes them easier to care for.
  2. Peaceful – You don’t want to worry about your fish fighting and getting injured.
  3. Small – Smaller fish need less water, which means you can get away with a smaller tank.
  4. Beautiful – You’ll want your tank to look bright and beautiful, so its good for fish to have some color.
  5. Interesting – Beginners can quickly become bored of fish that aren’t very active.
  6. Compatible – Some fish are simply better than others at sharing a tank.

Other popular freshwater fish often kept as pets include Goldfish and Bettas. They’re certainly good options, but with these fish, a little extra care is needed.

Bettas can be aggressive, particularly males defending their territory from other males.

And goldfish are not small fish. You may think goldfish are small, but that’s because the fish you see in pet shops are very young. Goldfish can grow to be 12 inches long, or even bigger!

If you choose a freshwater fish from our list of recommendations then you shouldn’t go far wrong. Though ultimately, the best type of freshwater fish to keep as a pet is personal to you. It depends on what you want, what size tank you have, and your experience and skill as a fish keeper.

What is the easiest freshwater fish to keep as a pet?

The easiest freshwater fish to keep as a pet would be a small, hardy fish such as the guppy, danio, tetra or molly.

Many people think that goldfish are also easy to keep, however they can grow to be very large and need a lot of tank space.

What freshwater fish are not aggressive?

Freshwater fish that are not aggressive include tetras, corydoras catfish, platies, mollies, roseline sharks and swordtails.

However, all fish have the potential to be aggressive sometimes. For example, when competing for territory, food or a mate.

What freshwater fish can be kept together?

Any freshwater fish that are not aggressive and that share similar water requirements can be kept together.

One good combination would be a community tank of live-bearers: guppies, platies, mollies, and swordfish. Perhaps with some corydoras catfish at the bottom of the tank too.

What do I need for a freshwater fish tank?

Essential aquarium equipment for a freshwater fish tank:

  1. Fish tank
  2. Water supply
  3. Water conditioner
  4. Filter
  5. Electricity supply
  6. Test kit (pH, ammonia, nitrite, nitrate)
  7. Thermometer
  8. Suitable fish

Optional items for a freshwater fish tank:

  1. Heater
  2. Air pump
  3. Lighting
  4. Substrate (gravel, sand, stones)
  5. Plants
  6. Decorations

It is possible to keep fish in a very bare tank, where all you would need is a filter and the ability to test and treat the tank water to ensure it stays within healthy parameters.

However, in reality, you will also need or want some items from the optional list. For instance, plants and decorations will make your tank more visually appealing and give your fish places to hide and explore.

Find out more about aquarium equipment and aquarium plants.

How much does it cost to set up a freshwater fish tank?

It’s impossible to say exactly how much it will cost to set up a freshwater aquarium, as it depends on the setup you choose.

The price will vary depending on the size of your tank, the kind of filter you need, and whether you buy other accessories such as air pumps and lighting.

Then there’s the cost of your fish, substrate, plants and decorations. And finally ongoing costs, such as food, water treatments and electricity.

We recommend researching and planning your tank carefully before buying anything. You can then add up the cost of everything you need any make sure it’s within your budget.

How hard is it to maintain a freshwater fish aquarium?

Maintaining a freshwater aquarium is not hard work. The biggest job is changing the aquarium water, but this shouldn’t be too much work as it’s best to change a small amount of water frequently rather than a large amount all at once.

You’ll also need to feed your fish, add water treatments and medicines as required, and maintain accessories such as your filter.

It’s important to remember that maintaining your aquarium isn’t a chore. It’s how you care for your fish and an important part of the fish-keeping hobby.

What kind of food do freshwater fish eat?

Types of freshwater fish foodWhat is it?
Dry foodThe classic fish food that most people think of, usually consisting of flakes, pellets or wafers.
Freeze-dried foodFoods that have been frozen and then had the water/ice removed. A popular example are freeze-dried bloodworms.
Frozen foodFood such as bloodworms and daphnia that has been frozen. You can then defrost it and feed to your fish.
Live foodThe same foods that are often frozen and freeze-dried – such as bloodworms and daphnia – can also be bought and fed live. However, there is a risk of introducing diseases to your tank.
Fresh vegetablesFish will happily eat various types of vegetable. Peas are particularly popular and can be good for digestion.

What is the best food for freshwater fish?

There is no one food that is the best food to feed to freshwater fish. Like humans, fish will be healthiest if they have a varied diet containing a range of vitamins, minerals and nutrients. This means you should try to feed your fish a combination of dry food, frozen or freeze-dried food, and fresh vegetables.

learn more about freshwater fish

And if you’d like to learn even more, we recommend exploring our freshwater fish articles or finding out more about saltwater fish, fish tanks, aquarium equipment, or aquarium plants.