Learn about exotic freshwater fish. With fish compatibility chart

What are freshwater fish and what do you need to know?

Generally people will start at this hobby motivated by how simple it seems to have a few colorful freshwater fish in a glass box with water in it but it is much more complex than that.

Freshwater fish are those that live in fresh water like lakes and rivers where there isn’t much salt in the water. They live in water that has a salinity of less than 0.05%. They are different from salt water fish because their environments are not the same as their marine counterparts.

colorful freshwater fish

When you think about an aquarium you have to understand the point is to imitate nature creating a simulation of an ecosystem where you can sustain different species in the best possible conditions and have them coexist in equilibrium.

Most of the time hobbyists will start with these kinds of fishes because they are easier to maintain and the conditions of the water of their native environments are also easier to replicate.
Still there are different kinds of fish even among the fresh water type.
Before setting up your aquarium it’s important you choose the type and species of fish you will have because that will decide the kind of water, the size of the tank and the total amount of fish you’ll be able to keep. For example if you have tropical fresh water fish you need to pay attention to the pH of the water. Each species has its own pH in which it can live comfortably. Usually fish can live between 5.5 and 8 of pH.
Finally you’ll need to take care of the temperature of the water, tropical fish for example usually live around 20° and 23° Celsius.

Choosing a freshwater tank

The freshwater aquarium gives us a great array of possibilities, because we can have a communitarian aquarium (a mix of different species of fish around the world, as long as they are compatible), a plant based aquarium (where the focus is on the natural plants instead of the fish, like in the dutch aquarium) or even an aquarium emulating a specific part of the world also called biotope (amazonic style, Malawi style, etc)
Each option has special requirements but most of the beginners start with a communitarian aquarium where the fundamental thing is to understand that the mix of species is something you have to plan from the start. Before adding new species you’ll have to know their behavior and if they are compatible with your current ones.

tropical fishwater fish can live here

Most of the starting problems people have are generated by the compulsive purchase of fishes, attracted by their colorful fins and shapes, creating complications inside the aquarium because of their aggressiveness, their lack of compatibility, their territorial behavior and that will cause problems and unbalance in the ecosystem

Taking into account most people will start with a freshwater tank these tips are given with that kind of setup in mind.
One of the most important aspects and certainly one that raises the most questions is the size of the tank. The proper dimensions will be dictated by the space we have available to install our aquarium, our budget and other aspects.

The ideal thing is for the aquarium to have less than 24 inches (60cm) in height so you can clean it and rearrange things with ease. If the box is higher you will need thicker glass and it could become very expensive for your first fish tank.
The depth should be of a minimum of 16 inches because the visual effect produced in the aquarium while looking at it when straight in front of it will make the posterior part of it to appear much closer.
The length of it will depend on our available space and finally on our budget.
If you need to calculate the volume you can use the following formula.
V= length (cm) x height (cm) x depth (cm) / 1.000

Once you have it placed you can customize it in many fun ways

Cool freshwater fish for beginners

You can use this short list to help you decide on new fish species for your freshwater aquarium or to start a new one. We’ve also added some nice rare aquarium fish.
Keep in mind not all of them are compatible with each other so it’s important you check with your local pet store or aquarium before you purchase anything.

Killifish: These are very versatile fish and can live in several types of water. You can have a hard water fish tank and these fish won’t have any problem coexisting with other animals since most of predators will ignore them. They have a great variety of colors and are perfect to give a dash of vitality to your aquarium.

madagascar rainbow fish

Bedotia geayi: A part of the Madagascar Rainbow fish family, these are small and colorful. They are ideal to keep other bigger fish company and are very sturdy. As long as they don’t experience a sudden change they can live in almost all kinds of water


Anostomidae: These are pretty big and can become larger than 5 inches, they tend to be of different colors, and they are independent and not very aggressive so they are great for midsize and large aquariums

exotic fresh water fish Catfish

Catfish: These will be almost all of the time at the bottom of the tank searching for food. They are almost mandatory for a midsize or large aquarium because they’ll help you keep it clean. There are several catfishes so it doesn’t matter what kind of aquarium you have you’ll find a catfish that can live in it.

Toxotidae: You probably know them because of the archer fish. The toxotidae will live at the top of your tank and will try to catch insects that fly above it. They hunt them down by shooting a few droplets of water from their specialized mouths. They will just ignore other fishes and cause no problems.

Blowfish: You’ve probably heard about Fugu, “the most poisonous fish in the world”. This doesn’t mean all of its relatives are equally dangerous. There is a great variety of blowfish that you can place inside your tank with no problems. While there are some rare freshwater fish in this species they tend not to be aggressive and can live with other peaceful species. We recommend you check with your local pet store before getting one to know how your specific kind of blowfish will react to the new environment

Common carp


Common carp: These freshwater fish are the most common ones in the world. You’ll be able to find carps in any fresh water aquarium in the world. Since this is such versatile and common specie it has developed a great resistance to different kinds of water and there is no fixed norm in particular for them.
neon fish
Characidae: These exotic freshwater fish vary in length but are really small and usually less than 3cm. They are tropical fresh water fish. They are a popular choice and many are important as food. Some of the most known ones are the neon fish and the piranhas (yes, you can buy piranhas as pets)

Fish compatibility chart

To achieve an equilibrium in your fresh water fish tanks you will not only have to pay attention to this fish compatibility chart because it’s centered only in the “social” aspect of the fishes. You will also need to take notice of the different chemical and physical properties of the water of each species. Some of them will do great in tropical warm water while others will need a hard water aquarium.
Also keep in mind that being in the same habitat in nature doesn’t mean they will get along so always check with your local aquarium before placing unique freshwater fish because you don’t want to place a predator in your fresh water fish tanks.

Chart courtesy of http://aquariumguide.weebly.com

fish compatibility chart