Best Freshwater Aquarium Fish

Choosing the right freshwater fish for your aquarium or pond is about more than just colour and appearance. Each species has its own unique needs, behaviours, and care requirements. In this guide, we explore some of the most popular freshwater fish, from vibrant bettas and peaceful guppies to resilient goldfish and long-lived koi carp. You’ll find essential information on ideal water temperatures, compatible tankmates, and feeding routines, helping you create a healthy and harmonious environment for your fish. 

Whether you’re a first-time fish keeper or an experienced aquarist, this resource will help you make informed decisions and keep your fish thriving.

Betta Fish

Betta fish, also known as Siamese fighting fish, are extremely beautiful. They come in an array of stunning colours, including blue, red, yellow, and orange, and are easily identifiable by their gorgeous flowing fins. 

Though betta fish are feisty, with the right care and preparation, they can be a great choice for dedicated fish owners. They are intelligent and interactive and will eventually recognise their owners. 

Where to keep betta fish

Betta fish are best suited to an aquarium environment. They do not tolerate sudden changes, so water temperature, pH level and cleanliness must remain consistent.

Due to this, it is easier to keep betta fish in an aquarium where the conditions of their environment are less likely to fluctuate.

Water temperature for betta fish

Betta fish require a water temperature between 76 to 85°F, or 23 to 28°C, and a pH level between 6.8 and 7.5. They can tolerate slightly warmer or colder water temperatures. However, if the water temperature strays too far away from the recommended celsius, it can significantly impact your bettas' health.

With this in mind, regularly checking the water temperature is crucial if you plan to keep bettas.

Betta fish tank mates

Betta fish are renowned for their feisty attitudes and territorial nature, so caution is crucial when looking for suitable tankmates for bettas.

Male betta fish will fight other male bettas, so you should avoid housing male bettas with each other at all costs. However, female bettas will live harmoniously together, and many people often keep around 4-6 female bettas together simultaneously.

Male betta fish can be aggressive towards other freshwater fish types, too – especially fish that are brightly coloured or have long fins and tails. With this in mind, it's important to ensure you provide bettas with a large tank and plenty of hiding spaces to prevent their territorialism.

Community tropical fish such as Tetras, swordtails, and guppies can be great tankmates for betta fish.

Betta fish diet

Freshwater betta fish thrive off a varied diet. In the wild, they regularly eat small insects as part of their diets, and you can find frozen alternatives in our fish food collections.

You should feed betta fish a varied diet of pellets and fish flakes. They can also be fed bloodworms for an occasional treat!

How often should you feed betta fish?

Like most freshwater fish breeds, betta fish will eat whenever they are fed, so it's important to follow a consistent routine. You should feed them at least once a day and sparingly so.

As betta fish are so sensitive to water cleanliness, look out for uneaten food and waste and scoop it out after feeding. This will prevent the tank from building up waste.

Bristlenose Plecos

Bristlenose plecos, also known as the suckerfish, is a popular member of the catfish family. They are bottom-dwellers that love to hide and are easily identified by their brown bodies. 

If you're looking for peaceful freshwater fish that will double up as tank cleaners, plecos will make a great addition to your tank. They live between 5-8 years, however, have been known to live up to 10 years if properly cared for. They require little maintenance and are perfect for people of all levels, including beginner and advanced aquarists. 

Where to keep Bristlenose Plecos

As tropical freshwater fish, plecos are best suited for a tropical aquarium where the temperature is consistently warm.

It's also worth remembering that plecos are bottom-dwellers who love to hide and seek shelter in their environment, so don't expect to see them often.

Water temperature for Bristlenose Plecos

Plecos need warmer water than most freshwater fish and will do best between 73 and 78°F, or 23 and 25°C. Plecos will quickly become sick if they are exposed to cold water temperatures.

They should be kept at a pH between 5.7 and 7.8 and a water hardness between 2 and 20 DH.

Bristlenose Plecos tankmates

Plecos are tranquil and peaceful and can be housed with various freshwater fish types. They spend most of their time at the bottom of their tank, so don't disturb fish that occupy their environment's mid and top sections. They live particularly well with guppies, neon tetras and mollies.

However, despite their peaceful nature, plecos should not be placed with other species of plecos, as this can cause them to become territorial and aggressive.

Bristlenose Plecos diet

In the wild, a plecos' diet mainly consists of algae, so it's important to replicate this in their environment. They also love to eat fish flakes, pellets, and bloodworms.

How often do you feed Bristlenose Plecos?

You should feed your plecos once or twice daily, offering enough food for them to eat within 10 minutes. As plecos are bottom-dwelling fish, be sure that their food sinks to the bottom of their tank so they can reach it.

Goldfish

Common goldfish are popular freshwater fish for beginners. They are resiliant, peaceful, and a fantastic way to introduce colour and vibrancy to your fish community. Though orange is the most common goldfish colour, they are also available in yellow, red, black and white. 

Where to keep goldfish

Goldfish are great freshwater fish for ponds and aquariums; however, they are likely to live longer if kept in a pond. No matter which environment you keep them in, they will require the same conditions concerning water temperature parameters.

Water temperature for goldfish

Goldfish are one of the most resilient freshwater fish types and can survive in various conditions, even low or freezing temperatures. However, the best water temperature for goldfish is between 68º and 76ºF, or 20 and 24ºC. They also require a water pH level between 7 and 8.

Best tankmates for Goldfish

Goldfish are generally friendly creatures and will get along with most freshwater fish types. They are not territorial or aggressive, but they like to scavenge – so it's best not to pair them with smaller freshwater fish breeds as they could be mistaken for food.

What can Goldfish eat

Goldfish are not too picky about what they eat. They are natural scavengers and, in the wild, will eat various plants and insects. You should feed your goldfish with flakes and pellet food to make up most of their diet. They will also love bloodworms as a healthy treat!

How often to feed goldfish

Goldfish will eat whenever they are fed, so it's important not to overfeed them. You should feed your goldfish small amounts of food around 2 to 3 times a day, Generally what they will consume within a few minutes. Make sure to remove any uneaten food.

Guppies

A guppy is a fantastic choice if you're looking for beatiful, peaceful fish to add to your community. Some guppies have flowing fins and long tails, whilst others have unique colours and markings. They live up to two years and are very easy to care for, making them particularly popular with beginners. 

Where to keep Guppies

Guppies are freshwater fish. However, they need warmth to stay active making them best suited to an aquarium environment.

Water temperature for Guppies

Guppies require a water temperature of 74 to 82°F, or 22°C to 28°C. They also need a water pH level of 6.8 to 7.6 and a hardness between 12 to 18 dH.

Guppy tankmates

Guppies are friendly, sociable fish that will get along well with most other fish breeds, including mollies and harlequin rasboras.

They enjoy the company of other guppies, so you should house them with at least three guppies before introducing other freshwater fish types into their environment.

However, just because guppies get along well with other fish doesn't mean that other fish will treat guppies in kind. Due to their small size, guppies can become a source of food for larger, more aggressive fish, so it's important to be cautious when choosing their tank mates.

Guppy diet

Guppies enjoy a varied diet and, in the wild, are known to eat a mix of algae, insects, and plants. You should try to offer a similar diet to your guppies and feed them regular fish flakes and blood worms as occasional treats.

How often do you feed Guppies?

Feed your guppies twice a day, ensuring only to provide as much food as they can eat within two minutes. Too much food can overload their digestive system and, if left over, will be detrimental to the water quality. With this in mind, remove any leftovers as soon as feeding time is finished!

Harlequin Rasbora

Harlequin Rasbora are small, hardy fish renowned for their peaceful behaviour and brilliant colours. They live between 5 and 8 years, and due to their easy maintenance, they are a great choice for beginner fish owners. 

Where to keep Harlequin Rasbora

Harlequin Rasboras are suited to a tropical aquarium environment. They love areas filled with vegetation, hiding places and a wide open space for swimming and exploring.

Water temperature for Harlequin Rasbora

A freshwater fish, the Harlequin rasbora is used to living in consistent, warm water. To ensure this fish is happy, keep the temperature between 72 and 81°F, or 22 and 27°C. They require a pH level between 6 and 7.8.

Harlequin Rasbora tankmates

Harlequin rasboras are peaceful and can be happily housed with various fish types, including neon tetras, mollies, and guppies. They can also live in harmony with snails and shrimp!

However, some less active fish species may not tolerate the rasbora's fast swimming and active lifestyle, so it's best not to house them with slow or timid fish. Rasboras may also be intimidated by or become prey to larger predatory fish.

Rasboras are school fish by nature, so you should always group them with at least 5-7 other fish of their kind before introducing other tankmates.

Harlequin Rasboras diet

This fish breed requires a highly balanced diet, including pellet and flake food. They also benefit from occasional feedings of shrimp and bloodworms.

How often do you feed Harlequin Rasboras?

You should feed harlequin rasboras once daily, feeding only as much food as they can eat in five minutes or less.

Koi Carp

Koi carps are among the most popular freshwater fish types, and unsuprisingly so. They are brightly covered, feature distinctive markings and patterns, and make a beautiful addition to outdoor ponds. They are also quite affectionate and will eat from your hands once they used to you. 

Like goldfish, koi carp are easy to care for, making them ideal choice for first-time and advanced fish keepers alike. 

Where to keep koi carp

Koi carp will adapt to whichever environment they are placed in. However, they are almost always better suited to outdoor ponds. They need lots of space and enjoy visiting every level your pond has to offer, so it's also important that your pond has a healthy depth with lots of shallow and deep areas to explore.

When kept in a large outdoor pond, standard koi carp can grow to their full potential, with some growing up to 36 inches long. They also live between 30-50 years, so it's important to realise your commitment before investing!

Water temperature for koi carp

Koi carp thrive best with a water temperature between 15 and 25°C and a pH of 7 to 8. However Koi can survive in cooler temperatures even when the pond freezes over. They are fairly tolerant of changes in the water temperature as long as the change is gradual. If the water temperature changes dramatically, your fish can experience shock, stress, and in worst cases death.

Like goldfish, koi carp are resilient. They are one of the hardiest freshwater fish types and can survive cold weather. However during extremely low temperatures, such as harsh winter weather, when the water is below 5°C, we would recommend adding a pond heater to prevent the whole pond surface freezing which will allow gaseous exchange.

Koi carp pondmates

Koi fish are known for their peaceful natures and will live in harmony with various other freshwater fish types such as goldfish. However, they prefer to live with other koi carp, so they should be kept in schools of at least 5 to ensure they are at their best.

Koi carp will interact with other koi fish and fish outside of their school, including goldfish, tench and Sturgeon. Goldfish are a particularly popular pondmate for koi, as they are similar in colour and look beautiful when swimming alongside one another!

Koi carp diet

Like goldfish, koi have huge appetites and eat whenever they are given food. With this in mind, it's important to be wary about overfeeding. They will feed at all pond levels and can be given pellets that will reach all depths!

They mainly eat plants and plant matter but are also known to eat seeds, algae, and insects. To ensure your koi carp are happy and healthy, you should regularly feed them supplemental foods such as wheat germ and fish foods high in protein.

How often do you feed koi carp?

Whilst most of your koi's diet will come from what they find in your pond, you should feed koi fish up to 3 small portions of pellet food per day. You can find everything you need to maintain your koi's diet in our fish food accessories range, from fish food and supplements to automatic fish feeders!

Mollies

Peaceful, entertaining, and beautiful to watch, mollies are a popular freshwater fish for beginners. They are easy to care for and live between 3-5 years. Despite their timid nature, they are also very active and love many plants, caves, and hiding spots to explore throughout the day. Its important to provide them with hiding spots to retreat to when they feel unsafe, and failing to do so may cause your fish stress. 

There are several species of molly fish, the most popular being black mollies, which have all-black bodies and rounded fins. However, you can also get dalmation, grey, and mixed orange, yellow, and white mollies. 

Where to keep Mollies

Mollies are not coldwater fish, making them at home in an aquarium setting. They are a hardy, resilient breed that can adjust to various water parameters, but their water temperature must remain consistent.

Water temperature for Mollies

Mollies can withstand various environments. However, if you want them to thrive, you should provide them with a water temperature that replicates their natural habitat. With this in mind, you should ideally keep them in a water temperature between 72 and 78°F, or 22 and 26°C.

They require a water pH level between 6.7 and 8.5 and a water hardness of 15 to 30 dH.

Molly fish tankmates

Mollies are peaceful fish that will happily live with many other freshwater fish types, including guppies and tetras. They can also be housed with snails and shrimp!

However, mollies are schooling fish, so they must be housed with at least four other mollies. You should buy one male for every two females to prevent the males from fighting for dominance.

Mollies should not be housed with aggressive fish, including bettas, as this can spark aggression in mollies.

Molly fish diet

Mollies enjoy a varied diet of plants and insects, particularly larvae. Algae is a huge part of their diet, in place of this, you can feed mollies spinach and lettuce!

How often do you feed mollies?

You should feed mollies twice a day, offering only a small amount of food each time. It should only be enough for the fish to eat continuously for two minutes, as any more than that may overload their digestive system.

Neon Tetras

Small in size but mighty in personality, neon tetras are one of the most popular freshwater fish breeds. They are renowned for their bright colours, stunning stripes, and peaceful temperament. 

Neon tetras are very easy to care for, making them a popular choice for beginner aquarists. They also have an average lifespan of 6-8 years and love to play and hide in underwater plants. 

Where to keep Neon Tetras

Neon tetras are tropical freshwater fish, so they must be kept in a consistent environment with tropical water temperatures that mirror their natural habitat. With this in mind, they are only suited for aquariums.

However, if the water is warm enough, they can be kept in an outdoor pond with a water heater. The temperature must remain high, and neon tetras must be brought back inside as soon as the temperature cools.

Water temperature for Neon Tetras

Neon tetra must be kept in water temperatures between 78 and 81°F or 21 and 27°C. Water colder than this will cause them stress and illness and make them more susceptible to disease.

For best results, you should keep neon tetra at a pH level between 6 and 7 and a water hardness between 2 and 10 dH.

Neon Tetra tankmates

Neon tetras are extremely friendly and should be kept in schools of at least six other tetras before other fish are introduced. When swimming in a school, they create a beautiful vibrant wave that will be a stunning focal point in your fish tank.

Their nature is peaceful, so they make suitable tank mates for other freshwater fish types, including other tetras species, cory catfish and barbs. They can also be housed with mystery snails and cherry shrimp!

Due to their small size, neon tetra can become a food source for larger fish, so it's important to bear this in mind when choosing their tank mates. It's also important that they are not housed with overly aggressive fish breeds, and if subjected to stress, neon tetras may engage in aggressive behaviour.

Neon Tetras diet

Neon tetras are omnivores and enjoy a varied diet that includes plant matter, algae, insects, and meat.

You should feed neon tetras high-protein fish flakes as a diet staple and offer live or frozen foods such as bloodworms or brine shrimp a few times a week.

How often do you feed Neon Tetra?

You should feed neon tetras twice daily, offering enough food for them to eat for two minutes each time. If you overfeed your tetras, they can quickly become ill, so it's important to stick to a controlled feeding schedule and to clear any leftovers from the tank.

Rainbow Fish

Popular for their bold and brilliant rainbow huesm rainbow fish are extremely popular amongst fish keepers of all levels. Despite their small size, they are extremely active fish that will take up a lot of space in your tank, so its important to house this breed in a large environment. 

Rainbow fish have an average life expectancy of 5-8 years. However, if well cared for, they can live up to 11 years. 

Where to keep Rainbow fish

Rainbow fish are tropical freshwater fish that prefer consistent water conditions, so they are suited to a tropical aquarium.

Rainbow fish must have lots of tall plants and areas to explore and a large open area to swim in.

Water temperature for Rainbow fish

Rainbow fish should be kept in a water temperature between 74–80°F or 23–26°C.

Though resilient, they do not fare well with water fluctuations, so the water temperature must remain consistent. You can use a heater to control the water temperature when the room temperature drops.

They also require a pH between 6.5 and 8 and a hardness between 10 and 20 dH.

Rainbow fish tankmates

Rainbow fish are renowned for their tranquil nature and will get along well with most other fish breeds. They thrive with more of their species and should be kept in schools of at least 6 or more rainbow fish.

They are not aggressive by nature. However, there are circumstances in which rainbow fish can become hostile. With this in mind, you should always keep more female rainbow fish than males to help reduce aggression and avoid housing them with other aggressive fish such as bettas.

Great tank mates for rainbow fish include angelfish, mollies, plecos, harlequin rasboras and tetra fish.

Rainbow fish diet

Rainbow fish are omnivores and so do best when given a varied diet. You should feed them a protein-rich diet filled with fish flakes and pellets and offer live food such as bloodworms and larvae as an occasional treat.

How often do you feed Rainbow fish?

You should feed rainbow fish three times a day, offering small amounts of food each time. It should only be enough for your fish to eat for up to three minutes.

Weather Loach

Weather loachers are one of the common freshwater coldwater fish. Also known as pond loaches, they are bottom feeders and tend to spend most of their time around the base of the aquarium or pond. 

Loach species are generally peaceful, easy to care for and live up to 10 years, making them a fantastic addition to all kinds of fish communities. 

Where to keep weather loaches

Hence their nickname, loaches, are popular freshwater pond fish. However they can happily live in an aquarium, provided they have lots of space to explore, hide, and rest.

Water temperature for weather loach

Different types of loaches have different needs and requirements, and water temperature is no exception. With this in mind, you should check the specific requirements of your loach species before introducing them to their environment.

Weather loaches do well in a water temperature between 59 and 77°F, or 15 and 25°C. They are known to tolerate temperature changes, provided they don't happen suddenly. Weather loaches may need to be brought inside during harsh winter conditions.

Weather loach tankmates

Loach are sociable and peaceful and enjoy living in small groups of their kind. They also live well with other fish breeds, as long as they aren't aggressive.

Weather loach diet

Loach fish are not picky eaters and will eat various things, including algae and vegetables. They will also eat insects and food pellets.

Snails are a particularly tasty snack for loaches, so we don't recommend adding snails to their environment unless it is for this purpose.

How often do you feed the weather loach?

Loaches should be fed twice daily, with enough food to eat within two minutes.