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Do You Keep Tropical Fish in a Freshwater or Saltwater Tank

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In the fish-keeping hobby, getting to know your species and providing the best conditions for them is paramount. You might have come to wonder whether tropical fish should be kept in freshwater or saltwater tank. Wonder no more! I have the answer for you!

Tropical fish comprehend a lot of species that could be either fresh- or saltwater. Each species will have its particular requirements, and the natural habitat will play a central role here. Freshwater tropical fish are more common among beginners since saltwater is thought to be more difficult. 

Believe it or not, tropical fish is an overgeneralization, and a myriad of species exist under it. Knowing your fish will allow you to provide the best possible conditions for them. Stay tuned to discover more about this!

What are tropical fish?

Tropical fish are species found in tropical waters all around the world. These species tend to prefer temperatures around 22 – 26 degrees Celsius (72 to 78 Fahrenheit.) Furthermore, these species are common in the fish-keeping hobby, thanks to their availability. 

Tropical fish require a submersible heater inside of the tank. With this device, they can have an environment with a controlled temperature. If the heater were not used, the fish could suffer from temperature drops.

Tropical fish are perfect for nano tanks, as they don’t need too much space to thrive. This is one of the advantages of having tropical fish instead of other varieties. 

Tropical fish tend to have beautiful colors and exotic combinations, making them a perfect addition to any aquarium. If you want to give vitality to your tank with marvelous colors, tropical fish might be the way to go.

Should I keep my tropical fish in freshwater or saltwater tanks?

Tropical fish can come from either fresh- or saltwater habitats. Since there are lots of species within the tropical fish classification, there are diverse preferences and requirements among them. The natural habitat of each species will dictate whether they should be kept in fresh- or saltwater aquariums.

These species can come from fresh- or saltwater regions, as long as they are tropical. There is nothing barring freshwater fish from being tropical, and the same applies to saltwater fish. The denomination comes from the areas they come from, not the water they prefer. 

Many beginners prefer to debut with freshwater species because these tanks are regarded as easier to maintain. If you are just starting in the fish-keeping hobby, you might want to begin with some hardy freshwater species. 

Bear in mind that there are not as many saltwater species available as there are freshwater. Saltwater species come from reefs, and they are not as accessible as freshwater species. 

Apart from that, saltwater species have proved to be more complicated to breed in captivity. That results in fewer species available in your local pet store. Freshwater species are more common and more readily available for you to acquire. 

You need to know the requirements of each species to determine if they should be kept in fresh- or saltwater tanks. Both options could be correct depending on the species we are talking about.

Be sure to do your research and don’t trust any overgeneralization about the care requirements of tropical fish!

Popular tropical fish for freshwater tanks

Freshwater tanks are a fantastic alternative for beginners since they tend to require less work than saltwater tanks. Moreover, you can create beautiful combinations between your plants and other species. 

These are some of the best tropical fish for freshwater aquariums:

Neon Tetra

You cannot go wrong with the neon tetra. This beautiful species will provide color to your tank and will create a healthy ecosystem. Neon Tetras are known to be calm and peaceful, making it easier to match them with other species.

Some aquarists call this species the gem of the fish-keeping hobby, and in the picture above, you can see why! These fish have a striking blue color all over their bodies that is only interrupted by a shiny red stripe towards the tail.

Neon tetras don’t usually grow over 2,2 cm. They like living in communities and in aquariums with lots of plants, rocks, and any other structure they can hide in. 

This species is perfect for beginners, as the neon tetras are relatively easy to care for. 


If you are looking for variety within the same species, guppies are a great option. These fish tend to have different color combinations, and the shape of their bodies also varies depending on male or female.

Guppies tend to have exotic color combinations, with male specimens standing out a bit more. Female guppies have milder colors and less showy body shapes. Both females and males can have different color combinations.

If you mix genders in your tank, you might find yourself with lots of guppies! These fish tend to breed rapidly, making it difficult to control their spread.

Other than that, they are easy to care for, as they have a high tolerance to temperatures. They can tolerate from 10 to 29 degrees Celsius around (50°F – 84°F,) making them perfect for beginners. 

Betta fish 

Looking for a fish with lots of character and ostentatious looks? Then the betta fish might be the species for you. However, you should know that these fish prefer big tanks to reach their full growth potential!

Betta fish can come in a wide range of colors. In most cases, they are red or blue with dashes of other tonalities. Betta fish can grow up to 3 inches. In general, these fish tend to be calm. Yet, when faced with other betta males, problems may arise.

Male betta fish tend to be aggressive and territorial around other males or other similar species like guppies. If you want to keep more than one betta in your aquarium, you should only keep one male.

Be careful with the compatibility of this species with others to avoid any aggression between them. 

Popular tropical fish for saltwater tanks

Many aquarists regard saltwater tanks as harder to keep. Yet, you can have a thriving saltwater tank with the correct information. Moreover, you can add some astonishingly gorgeous fish to it.

Here you have some of the most popular tropical fish for saltwater aquariums:


Perhaps you loved it, perhaps you hated it, but you must have seen the funny clownfish on Pixar’s Finding Nemo. With the movie, this species became even more known both inside and outside the aquarist world. 

Clownfish have this marvelous combination of bright orange, black, and white. These colors make clownfish incredibly attractive to the eye. It is hard to ignore them!

These fish are highly active and like to remain in the open; they don’t usually hide. Clownfish are easy to care (and can live pretty long) for and can be a good match for beginners.


Some fish can amaze you with their colors; others, with their shape. And then, there are the tangs. These fish can dazzle you with their bright variety of colors and their oval-shaped body.

Tangs can have one intense color or different marks and stripes. The possibilities with the color are limitless, ranging from bright yellows to deep intense blues. Apart from the colors, the oval-shaped body gives personality to the looks of this species.

Tangs need a lot of space to live happily. In some cases, they need tanks of up to 100 gallons. I know this can be a bit too much, especially if you are just a beginner. Yet, the beauty of tangs is worth giving it a thought!

Another thing to consider is that tangs can be aggressive to other tangs. They tend to socialize without problems with other tank fish. Yet, they can be territorial with other specimens of their own species. 


Some fish can add life to a tank thanks to their rapid swimming and bright colors, and the firefish is one of them. Few fish could win a race against this speedster of the waters. It is a delight to watch them moving rapidly around a tank.

These fish have a light or white semi-translucid body, embellished by a deep red or magenta tail. These colors come together to create a striking image when the firefish speeds around the tank.

It is preferable to keep this species in a calm and peaceful tank. Firefish are not likely to look for trouble with other species. However, they will outswim any tank fish that tries to prey on them. 

You won’t regret adding this lively fish to your saltwater tank! They are not only beautiful but also fun to watch.

These are just some of the species that you would find for each classification. However, there are many more for you to choose from. Whether you decide to go for freshwater or a saltwater tank, there will be plenty of colorful tropical species waiting for you.

Having fish has been an amazing experience for me, so I can only recommend this wonderful hobby to you!

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