Tropical Freshwater Fish for Aquarium

There are many tropical species in all parts of the world. For this reason, it is not easy to decide which are the best freshwater tropical fish for our aquarium.

Here we show you a selection of the main tropical water fish to help you choose the most suitable for your tank.

If you want to set up your tropical tank and have doubts about how to do it, you may be interested in our Guide to setting up a tropical freshwater fish tank. Learn step by step how to set up your own tropical aquarium.

If you are not entirely sure that yours is a tropical tank, you may be interested in having more information about the types of fish that you can have in an aquarium.

Tropical freshwater fish for aquarium

By informing yourself well, you will be able to avoid future problems for your friends, the tropical freshwater fish, and you will enjoy their relaxing company.

Here are some specimens of freshwater tropical fish.


These warm freshwater tropical fish originate from South America. They inhabit low-lying streams of rivers, ponds, and lakes.

The water temperature should be between 23 and 27 degrees, although the ideal is 25 degrees. The pH of the water should be slightly alkaline, ideally between 7.0 and 7.2 and a hardness of 10 to 20 dH.

It is recommended not to have more than one Guppy for every 5 liters of water, with an aquarium of at least 40 liters since they are very restless and need space to swim.

To stabilize the water a good filter like this should be used. They need decorative elements and plants to hide. They are extremely sensitive to copper sulfate which can kill them.

Its diet is very wide: it ranges from foods rich in protein such as artemia, water flea… to vegetables or cooked peas since it is an omnivorous fish. Avoid overfeeding as it can cause intestinal diseases.

The males are smaller, measuring from 2 to 4 cm, the females from 3 to 5 cm. The males stand out for their beautiful red, blue, green or brindle colors.

This species usually lives around 3 years, compensating with its great reproductive capacity (they are oviparous) and reach maturity at 3 months. If you want to know more about these tropical fish, our Guppy fish – Roecilia Reticulata care guide can help you.

Rainbow fish

These beautiful and colorful tropical fish, native to the warm waters of New Guinea and Australia, are very active swimmers and need large aquariums to move around.

The Rainbow Goby (Melanotaenia boesemani) needs a tank size of 80 liters, a temperature between 23 and 26º and a pH between 6.5 and 7.5. The water must be well oxygenated with a large filter.

The bottom must have gravel or sand or a mixture of both so that it can be moved and sheltered. You can also have aquatic plants that encourage the growth of algae, which is their main food.

It is basically herbivorous, although it accepts scales and red worms in the aquarium, which should be limited to avoid intestinal problems.

They have the peculiarity of changing color depending on their mood, varying from light green to dark brown and they usually measure 7 cm.

betta fish

The beauty of the colors (the result of numerous crosses and hybridizations) and the majesty of movement in the males make them very popular tropical fish.

With a fish tank size of 50 liters, between 22 and 30 degrees, and a pH of between 6 and 8, you can have these specimens between 4.5 and 10 cm. known as fighting fish, implying the fierceness of this species with its congeners.

Although there are also some species of Betta that live perfectly with other males, as long as there are enough females and space. The colors in the males are more spectacular and striking.

They belong to the family of labyrinths, named for the accessory respiratory organ that allows them to breathe air directly, when in stagnant or boggy water.

The aquarium must have a vegetal cover and also surface vegetation so that it can create its bubble nests, avoiding water currents. To get moist and warm air on the surface of the tank, it is recommended not to fill it completely.

To ensure their color they should be fed dry products with a high protein content like this one that you can see if you click here, also adding small insects to their diet, without overfeeding them as they tend to become obese.

Angel Fish

The angel fish or scalar fish must have a 100 liter aquarium and the water must be between 24 and 30 degrees, the pH must be between 6 and 7.4.

These tropical fish are a fairly resistant species that withstand unfavorable conditions in the tank, although not continuously. They reach 15 cm in length and 20 cm in height, with no clear differences between the two sexes, and they are very fast and agile.

Depending on whether we are going to have a single pair or more specimens of these fish, we must have a 100-liter tank (200 liters if we have 4-5 scalars) covered with tall, leafy plants that help proper biological filtration.

We must also have a filtration in conditions like this that you can see here to eliminate the waste.

They are very sociable and so that they do not get stressed (and can die) they need to live accompanied. Generally peaceful in nature, although they can modify their behavior when feeling stressed or threatened, this affecting their appetite or even their life expectancy.

To achieve a reproduction of the ecosystem of origin, the ideal is to have broad-leaved plants, and branches and trunks where it can take refuge.

They are omnivorous and feed on dry food, complementing it with frozen or live food, dividing the food into two not very abundant meals. They are gregarious when young and very docile, and when they find a partner it is for life.

In the breeding season they can behave more territorially, and usually have a life expectancy in captivity of 3 to 6 years.

cardinal tetra

The paracheirodon axelrodi, better known as the cardinal fish, needs a 60-liter tank and a water temperature of between 23 and 27º. The pH should range between 4.6 to 7.

They are active swimmers, so these freshwater fish need wide spaces to move. They have a small size and in the fish tank it does not exceed 5 cm in its adulthood.

Its colors are red, although they are also found in gold, albino and platinum colors, with a green-bluish stripe that crosses it longitudinally.

Until they reach adulthood, it is difficult to distinguish the sexes, the females being rounder and larger.

They usually swim in the intermediate zones of the aquarium, which must be densely planted to provide them with shelter, especially in the breeding season. Captive breeding is quite difficult.

The aquarium lighting should not be very intense, and they eat all kinds of live or dry food as they have a voracious appetite.

They are peaceful within a school of 8 to 10 individuals, seeking mates of similar size within characins, avoiding corydoras and medium cichlids.

Elephant Fish

The elephant fish (Gnathonemus petersii) is a tropical freshwater fish that needs a tank of 100 to 200 liters, 24 to 28º and a pH of 6 to 6.5.

If you want to have more than one specimen, the aquarium must have between 300 to 400 liters. They are very sensitive to the concentration of nitrates, so good water quality is needed to avoid diseases.

Plants should abound on the bottom, which should be sandy, as well as floating plants, soft light, and hiding places such as rocks, roots, and logs. In the fish tank it does not usually exceed 23 cm but in freedom it can reach 35 cm in length.

Colors range from dark brown to very dark gray almost black.

They produce small nerve impulses that allow them to avoid obstacles in the dark and to find their way around, pursue prey in murky waters, recognize and find a mate.

Feeding is very specialized and they should be fed when they are most active, which is at the end of the day. Captive breeding is not possible and life expectancy is 5 years.



They are very colorful tropical fish and like to bury themselves in fine gravel. This must be taken into account, because if they cannot hide, they do not rest and could become stressed.

Their activity occurs mainly at night and they react to variations in atmospheric pressure by swimming along the walls of the tank or by circling.

Its size is from 8 to 11 cm. It eats both live and frozen animals, but the food must fall to the bottom of the tank or it won’t eat it.

Salmon/yellow in color with dark brown to black stripes and a white stomach. His life expectancy is 10 years. Reproduction of these tropical freshwater fish in the aquarium can be tricky, and pairs must be grouped together.

Convict Cichlid

The Cichalasoma Nigrofasciatum, known as the Convict Cichlid, needs an urn with a minimum size of 150 liters for a single couple and a water temperature between 22 and 27º, decorated with stones, roots and trunks.

The bottom must be sandy, since in the breeding season the males dig nests to lay their eggs. The recommended pH is between 6.5 and 8.

The size can reach 15 cm, although the females are smaller, and it has a very aggressive character, so coexistence in the tank is not easy, especially during the breeding season.

But they are very resistant fish, which makes them a good acquisition for beginners without much experience, they can survive in various environments, with great adaptability.

You have to control their ovulation with the temperature of the water to prevent them from dominating your tank, as they have a fast reproduction.

This species of tropical fish is omnivorous and likes dry food such as scales, sticks, live food, etc.


These tropical friends, belonging to the Siluriformes order, need a large tank: 250 liters with a temperature of 21 to 27 degrees, and a pH of 6.5 to 8. The catfish or catfish is the typical fish that is sold as aquarium cleaners, although there are more species with that quality.

They have a sucking mouth and are usually hung on the glass of the urn or glued to the stones at the bottom. It is difficult to distinguish the sexes although the females seen from above seem wider.

This kind of tropical freshwater fish can reach 60 cm but in captivity it does not exceed 35 cm. Being a large specimen, it needs a very large fish tank with a substrate of sand and peat, and hiding places to hide, with abundant and well-planted vegetation.

They are vegetarian fish and great consumers of algae but they also accept frozen food and worms, cucumber, lettuce, etc. During the day they remain hidden, and at night they come out to eat.

They have a friendly temperament towards other species but it is not advisable to have several specimens, thus preventing them from behaving aggressively. In captivity they do not usually reproduce.

To choose optimal specimens they must have a rounded belly and their eyes must not be sunken.


They can measure between 15 and 35 cm and reach a weight of 1.5 kg. It is potentially colonizing being a great threat to native specimens as well as ecosystems and habitats.

The introduction of these tropical fish into the natural environment is prohibited as they are classified as an invasive alien species.

The color varies from olive green to black depending on the humus content of the water.
The young specimens feed on plankton and the adults on a variety that includes insects or smaller fish.

Its natural habitat is rivers and lakes, with a slow and oxygenated current with abundant vegetation.

Males reach sexual maturity around 2 or 3 years of age and females around 4 or 5 years of age, spawning in spring in shallow waters.

Tiger Barbel

Puntius tetrazona is a species of tropical fish that needs a large fish tank, 100 liters and a temperature of 23 to 28º, with a pH of 6.7 to 7.

They reach 7 cm in length when they are adults and have a wide range of colors depending on the species. The male is more slender, but also smaller and thinner and more intensely colored.

It can coexist in a school of 6 and 10 specimens, this will prevent it from causing problems for other species.

Aquariums should have sand substrate like this or it can also be dark pebbles with room to swim and hide.

Being very active tropical fish, they need a large amount of oxygen, so it is necessary to have an adequate filtering system. It is an omnivorous fish and eats all kinds of frozen or dry food, although it loves small live prey.

To avoid aggressive attitudes towards other species, it is advisable to breed them in small groups of 6 to 8 individuals.

The Tetras and Cobítidas are ideal companions for the Barbel. Reproduction in the tank is quite easy if they have the optimal conditions for it.


Belonging to the Serrasalminae subfamily, these large warm freshwater fish need a large tank, 350 liters and with a temperature of 22º to 28º C. The pH should be between 5.5 and 7.5.

The bottom must be sandy, with abundant vegetation and enough places where it can shelter and hide and soft lighting.

These warm-water tropical fish can grow to a large size, 25-30 cm in captivity and 40-50 cm in the wild, and their color varies depending on the variety.

The difference between the sexes is evident as the males have a solid and thicker head, while the females have a rounder body.

They have a life expectancy of 5 years, although in the wild they can live up to 30 years.

Being carnivorous, it feeds on invertebrates, insects or small fish. They can also be given dry food, avoiding poultry and mammalian meat as they do not metabolize the lipids contained in these meats.

With other species they are very aggressive, hostile and territorial, which makes coexistence with other species, even those of the same family, very complicated. Its reproduction is quite difficult.


They are especially striking due to the impressive metamorphosis of colors that occurs in males when they mature sexually. The colors range from blue or yellow, to red or orange when they come from captive breeding.

In general, they do not require much care and are easy to maintain and reproduce. They are peaceful fish and for this reason they can coexist with species of similar character.

Depending on the variety, its size is between 13 and 18 cm. The length of the fish tank must be at least 100 cm.

It needs alkaline waters with a constant pH between 8 and 8.5 and rich in calcium and magnesium carbonates, which help to intensify its color. The temperature should be constantly between 25 and 27 degrees.

It should be kept in tanks with equal decoration of rocks and sand bottoms, installing an effective filtering system for fish tanks, to create currents.

Being omnivorous and very voracious, you have to control their diet, which is very wide: from scales, stickis, frozen foods, mussels, white fish, etc.

Until they reach sexual maturity, the sexes are not distinguished, and during the mating season they become aggressive with their congeners while with other dominant species they are skittish.

For reproduction, it is best to keep several females per male, providing each one with a refuge.


Its reproduction is simple as well as its care. Brightly colored and well developed fins.

Being a very territorial fish, it is convenient that you make sure of its compatibility with other species, thus avoiding conflicts between them. The aquarium must remain covered, this will increase the humidity.

Its main features in morphology are the protractile mouth and jaw. They don’t have teeth. They can live in rivers or lagoons and small ponds, and this influences the time of reproduction.

The Labyrinthid family is made up of 4 subfamilies that encompass 13 genera with 91 different species. Depending on the species, the size varies, but they are very attractive fish for aquarium enthusiasts.

Characteristics of Tropical Fish

If you want to know more about marine fish you can take a look at our guide to saltwater fish for aquariums.

Where do tropical freshwater fish live?

The care and maintenance of warm water tropical fish, like cold water fish, does not require much time or knowledge, but you must take into account a series of tips and guidelines to ensure that your fish tank is in optimal conditions.

With this you will ensure that the inhabitants of your fish tank have a healthy home.

One of the most important things to consider with tropical freshwater fish is the temperature of the water. Depending on the origin of the species, in this case tropical freshwater fish, the water must be kept at a certain temperature.

What is the ideal temperature for tropical fish?

If the conditions of cleaning and feeding that are provided to them are good, they can adapt to a lower degree in water temperature.

There are several techniques to regulate and maintain water temperature.

The most basic is the use of a thermometer, like the one you can see here, which will provide us with constant and accurate information. So that it does not give us an erroneous reading, it should not be oriented or placed near sources of heat, such as lamps or direct sunlight.

There is also the fish tank water heater, which helps us control the temperature by raising it through heat emission in a controlled manner, being able to regulate it.

Exposing the fish tank to the sun is a harmful method that can also generate other problems such as algae.

Once the right temperature is achieved, to achieve a correct coexistence between tropical freshwater fish, you have to choose those that are compatible. This way you will avoid problems of territoriality or aggression between species.

Another parameter that is very important is the pH of the water. The pH in which fish can generally live in a healthy way is between 5.5 and 8.

What tropical freshwater fish are compatible?

Owning a tropical tank can be one of the best experiences for lovers of aquatic nature. But before mixing different species of tropical fish, it is necessary to understand the interactions that these will have in the same space.

In many cases, you can find several species of tropical fish that can be mixed in the same tank. However, there are also many species that cannot live together.

Fish that don’t get along will add a lot of stress to the tank. Some fish become so aggressive that they intimidate or kill each other. Understanding why fish fight can prepare you for your own tank.

Why do fish fight?

One of the main reasons for negative interactions between tropical fish is competition. Fish that don’t get along often chase away rivals to fight over resources such as food, rocks, plants, and other items in the tank.
Although fighting over territory sounds similar to fighting over resources, it’s a bit different. Some fish are more territorial than others. If the tank is too small, they may start chasing each other in an attempt to free up space.
personality clash
Certain species of fish are known for their shy tendencies, while others are considered » fighting fish. » Researching the fish you want to include in your aquarium should always be the first step.
Depending on the species, care may need to be taken when it comes to the ratio of females to males. Some fish may fight each other for breeding rights.

Keep reading and we will give you a few lists with the types of tropical fish that should and should not be companions in a tropical fish tank.

What tropical fish can live together?

Please note that this is only a basic guide to follow. The rules can always be modified. Fish have personalities like dogs, cats or even people. We have had very aggressive fish that cohabit with calm fish, for example.

Below is a list of tropical freshwater fish species that can, for the most part, cohabitate in the same tank:

  • guppies
  • tetras
  • molly
  • plates
  • small catfish
  • Cory’s
  • danios
  • small gouramis
  • little plecos
  • Raspboras
  • Swordtails

Which tropical fish should not share the same tank?

To avoid aggression between your new friends, keep this list in mind. These fish are best kept with individuals of the same species:

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