Keeping adorable fish at home can be a brilliant way to boost your mood. If you are a beginner who needs to keep things simple, you may want to start with a 2.5-gallon fish tank that is easy to maintain.

But when it comes to the best fish for a 2.5-gallon tank, there are fewer options than the large ones.

Mini tanks can easily sit on your desktop and cleaning them won’t be a big deal. Quite similar to larger aquariums, 2.5-gallon tanks are commonly made of acrylic which doesn’t require high maintenance.

How much does a 2.5 gallon fish tank cost? Find out here.

If you are interested to use this tank, you’ll want to know suitable fish that fits in it.

Due to the small size, you don’t have that many options for fish. It also limits the quantity, just to make sure they have enough room to swim around.

Take a closer look at potential fish below and make your own choice.

Best Fish for 2.5 Gallon Tank at Home

Here are some of the more suitable fish for around 2.5 aquariums in your beloved home.

Betta Fish

Red-orange betta fish (Source:

On the top of the list, there is betta fish which has become a small aquarium favorite for years. Is a 2.5-gallon tank big enough for a betta fish? The answer is yes.

Adult bettas can grow up to 2.1 inches, which is ideal for small acrylic tanks—even some keepers put them in a bowl, which is not recommended.

Bettas are born as a fighter and they are quite aggressive. Betta fish can attack any other fish in the same tank, so it is important to keep them in a separate aquarium.

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Despite their aggressive behavior, bettas are susceptible to health issues. To keep your fish healthy and thriving, be sure to clean the tank regularly. Keep the water clear and toxic-free, in addition to giving a healthy diet.

Small Barbs Fish

Betta fish alternative: small barb fish (Source:

Pretty much like bettas, adult small barbs fish can reach up to 2 inches. They are ideal for beginners because of their easy maintenance.

There are different types of barbs but the most ideal for smaller tanks are checkerboard and cherry barbs.

Not only are barbs easy to care for, but they are also visually attractive.

Viewing these fish swimming in your tank can be a great way to heal your mind and soul. They are also aggressive and tend to fight with other fish species.

For a 2 – 2.5 gallon tank, you can keep up to 5 small barbs. Don’t add more than five as it will make the space too crowded. Give them enough space to show their strength.

Cory Catfish

White cory catfish (Source:

Cory Catfish is another ideal fish that can live in a 2.5 gallon tank. Coming with beautiful coloration, adult fish can reach up to 2.5 inches which is suitable for small aquariums. But before keeping this fish, it’s worth noting that they don’t like to live alone, or else they will die.

To make them happy and healthy, you may want to keep them in a small group. Make a group of three for each tank and they won’t feel lonely.

Don’t forget to maintain ideal water conditions, including pH and water temperature to keep them growing.

Small Tetras

Cardinal tetra (Source:

Small tetras can be a great addition to your 2.5 gallon tank. With a peaceful temperament and easy maintenance, they are ideal for fishkeeper newbies.

Besides, they are also available in different variants, such as neon tetra, lemon tetra, cardinal tetra, and black tetra.

Small tetras love to hide, so you may want to add some live plants into the tank (you should read our article on recommended red aquarium plants). It is also necessary to monitor the ideal tank temperature between 77 and 82 degrees with an ideal pH level between 5 and 7.

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How many fish for a 2.5 gallon tank if you choose tetra? Make a group of 2 or 3 and they will be fine.


Multicolor danios (Source:

Danios is small, easy to care for, and adorable. Beginners who just began with fish keeping can opt for this species for it doesn’t require extra effort. Adult fish can reach up to 5 inches, which means they are suitable for a 2 to 2.5 gallon tank.

With the perfect water temperature between 70 and 78 degrees and the ideal pH level, they will survive in your home aquarium.

Most Danios are active and they feed on almost anything. Whether you don’t have time or skill for extra maintenance, this fish type is surely for you.

Black Molly

Black molly (Source:

Black Molly is one of the small aquarium favorites among aquarists. They have distinctive black coloration over the entire body, making them a unique addition to your mixed aquarium.

Adult black molly fish can grow up to 3 inches and they will be happy if you keep their tank clear.

One of the most popular things about black molly is that the females give birth and they tend to eat the babies.

You can keep a male and female in the same tank but when the female is ready to give birth, make sure to move it and protect the babies.

White Cloud Mountain Minnow

1-1,5 inches White Cloud Mountan Minnow (Source:

What fish for 2.5 gallon tank that is easy to keep? The answer could be white cloud mountain minnow. Their size ranges between 1 and 1.5 inches, making them tiny creatures to add visual appeal to your freshwater tank.
These fish are characterized by yellowish coloration on their bellies and a white line.

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White cloud mountain minnows are quite similar to tetras. Hence, you can keep them in the same tank.

It can thrive in many water conditions and temperatures, but it will thrive better in-tank temperatures ranging from 60 to 72 degrees.

Small Live Bearers

White Small Live Bearers (Source:

If you have few fishkeeping skills, you may want to try small livebearers. Caring for these fish can be a bit challenging because of their tiny size which ranges from ½ inches to ¾ inches.

Despite their tricky maintenance, these fish are cute and mesmerizing with a wide variety of colors.

With their small size, you can keep many of them in a single tank. But you should keep in mind that small livebearers have a high breeding cycle and they can grow in numbers faster than expected.

Black Skirt Tetra

Black Skirt Tetra with vertical stripes (Source:

Black skirt tetras are beautiful blackfish with a distinctive appearance. They have noticeable vertical stripes that help distinguish them from other species.

Adult skirt tetras grow up to 2 inches, so you can add 3 to 4 of them in a 2.5-gallon tank.

With excellent maintenance and a supportive environment, black skirt tetras can live up to 5 years. Regularly change the water and feed on a healthy diet so they can thrive.


Platy fish swimming on tank (Source:

Platies is a decorative fish species that is suitable for a 2.5 gallon tank. It has a vibrant coat with black coloration on its fins, making them easy to recognize.

With the average size of platies between 2.5 inches and 3 inches, they fit well in your small tank.

There are different colors of plates to choose from, such as yellow, blue, orange, and red. They are completely easy to maintain, so beginners can opt for this species for learning fishkeeping.

They also have a good temperament, allowing you to mix them with other fishes.

Recommended 2.5 Gallon Tanks

Aqueon LED Small Aquarium Fish Tank4.5/5
Koller AquaView Fish Tank4.0/5

Final Words

Now that you know the best fish for 2.5 gallon tank, it is much easier to find ones that meet your preferences.

Because of space limitation, pay attention to how many fish to add to the tank. Just make sure they have enough room to swim around.