Top 10 Most Popular Aquarium Fish and How to Care for Them

Creating the perfect home for your aquarium fish can be a deeply rewarding experience. Whether you’re starting with a small tank or going for a larger setup, choosing the right fish and understanding their care needs is key to keeping them happy and healthy. Below is a detailed guide to the top 10 most popular aquarium fish, offering insight into their personalities, care requirements, and tank needs.

1. Betta Fish (Betta splendens)

Type: FreshwaterLifespan: 3-5 years
Tank Size: Minimum 5 gallons (10+ gallons preferred)
Environment:

Temperature: 75-80°F (24-27°C)
pH Level: Slightly acidic to neutral (6.5-7.5)
Hardness: Soft to moderately hard water

Care Needs:Betta fish, often called “Siamese fighting fish,” are popular for their dazzling colors and flowing fins. They are relatively easy to care for but require specific conditions to thrive. Betta fish are solitary creatures, particularly males, and should be housed alone to avoid territorial fights, especially with other males. A female betta may live peacefully with others, but they must be closely monitored.

Their tank should have a lid since bettas are known to jump. The substrate can be sand or smooth gravel, as rough surfaces can damage their delicate fins. Betta fish prefer well-planted tanks with hiding spots, so adding soft plants like Java moss can help make them feel secure.

Feed them a high-quality betta pellet or flake food designed specifically for their dietary needs. You can also give them occasional treats, such as bloodworms or brine shrimp, to keep them engaged. Regular water changes are essential to keep the water clean, and filtration is recommended for maintaining water quality.

How Many Per Tank: 1 male per tank; females can be housed in a small group, but always observe their interactions to prevent aggression.

Fun Fact: Betta fish have labyrinth organs, which allow them to breathe air from the surface, meaning they can survive in lower oxygen environments compared to other fish.

2. Neon Tetra (Paracheirodon innesi)

Type: FreshwaterLifespan: 5 years
Tank Size: Minimum 10 gallons
Environment:

Temperature: 70-81°F (21-27°C)
pH Level: Slightly acidic to neutral (6.0-7.0)
Hardness: Soft to moderately hard water

Care Needs:Neon tetras are peaceful, colorful, and perfect for a community tank. These small fish are characterized by their brilliant blue bodies and glowing red tails, making them one of the most sought-after aquarium fish. Tetras are best kept in schools, as they are social and feel more comfortable and secure when surrounded by their own kind. A school of 6 or more neon tetras will display their most beautiful colors, especially in a well-maintained tank with plenty of plants.

While neon tetras are hardy, it’s essential to keep their water quality high. A gentle filter is recommended to avoid stressing the fish. They are omnivores, so they will enjoy a variety of foods, including high-quality flake food, micro pellets, and occasional live or frozen foods such as daphnia or brine shrimp.

How Many Per Tank: At least 6-10 neon tetras to allow them to school and feel safe.

Fun Fact: Neon tetras are often used in biotope aquariums that replicate the Amazon River basin where they naturally live.

3. Goldfish (Carassius auratus)

Type: FreshwaterLifespan: 10-15 years (some live even longer with proper care)
Tank Size: Minimum 20 gallons for a single fish
Environment:

Temperature: 65-75°F (18-24°C)
pH Level: Slightly alkaline water (pH 7.0-8.4)
Hardness: Soft to moderately hard water

Care Needs:Goldfish are a timeless favorite, known for their elegant appearance and longevity. These cold-water fish are easy to care for but require a larger tank than many people initially realize. Goldfish produce a significant amount of waste, so regular water changes and an efficient filtration system are crucial for maintaining water quality.

Goldfish are not picky eaters but benefit from a varied diet. They can be fed high-quality goldfish pellets or flakes and supplemented with occasional live foods such as daphnia, worms, or peas. You should avoid overfeeding them to prevent water pollution and health problems.

A common misconception is that goldfish can live in small bowls, but they actually need large, well-maintained tanks to thrive. They should also be kept with other peaceful, similarly-sized fish.

How Many Per Tank: 1 goldfish per 20 gallons. If you have more than one, increase the tank size accordingly, as goldfish can grow large.

Fun Fact: Goldfish are one of the oldest domesticated species, with evidence of them being bred in China over 1,000 years ago.

4. Guppy (Poecilia reticulata)

Type: FreshwaterLifespan: 2-3 years
Tank Size: Minimum 10 gallons
Environment:

Temperature: 72-82°F (22-28°C)
pH Level: Slightly alkaline (7.0-8.0)
Hardness: Soft to moderately hard water

Care Needs:Guppies are one of the most vibrant and colorful aquarium fish, with various shades ranging from blues and reds to yellows and greens. They’re small, hardy, and easy to care for, making them an ideal choice for beginners. Guppies are social and do best in schools of 5 or more. Keep in mind that guppies are livebearers, meaning they give birth to live young rather than laying eggs.

They can be housed with a wide variety of other peaceful fish. Guppies are omnivores and will enjoy a diet of high-quality flake food, supplemented with occasional live or frozen foods like bloodworms or brine shrimp.

How Many Per Tank: 3-4 guppies per tank, with a ratio of 1 male to 2-3 females to reduce stress and prevent unwanted breeding.

Fun Fact: Guppies are often called “million fish” due to their ability to breed quickly in the right conditions.

5. Corydoras Catfish (Corydoras spp.)

Type: FreshwaterLifespan: 5 years
Tank Size: Minimum 20 gallons
Environment:

Temperature: 70-78°F (21-26°C)
pH Level: Slightly acidic to neutral (6.0-7.5)
Hardness: Soft to moderately hard water

Care Needs:Corydoras catfish are peaceful bottom dwellers that add charm and character to any tank. Known for their “armored” plates, these fish are great for cleaning up leftover food that sinks to the bottom of the tank. Corydoras enjoy being in schools of 4 or more, as they feel safer and more comfortable in groups.

Their tanks should have a soft substrate (such as sand or fine gravel) to prevent damage to their barbels. Corydoras are social and peaceful, making them great companions for other non-aggressive species. They eat sinking pellets and will also appreciate occasional treats of live or frozen foods.

How Many Per Tank: 4 or more, as they are highly social and enjoy the company of their own species.

Fun Fact: Corydoras are known to “dance” as they swim along the bottom, often in search of food.

6. Angelfish (Pterophyllum scalare)

Type: FreshwaterLifespan: 10 years
Tank Size: Minimum 20 gallons
Environment:

Temperature: 75-82°F (24-28°C)
pH Level: Slightly acidic to neutral (6.8-7.8)
Hardness: Soft to moderately hard water

Care Needs:Angelfish are stunning, graceful fish that require a bit more attention due to their size and temperament. Known for their tall, triangular body shape and long, flowing fins, angelfish are best kept in tanks with plenty of vertical space. They may show territorial behavior, especially during breeding periods, and they are not ideal for tanks with smaller or more peaceful fish.

Angelfish should be fed a balanced diet of high-quality flakes or pellets, supplemented with occasional live or frozen foods. They prefer a well-planted tank with plenty of hiding spots. It’s important to avoid overcrowding, as angelfish need space to grow and display their beautiful fins.

How Many Per Tank: 2-3 angelfish in a 20-gallon or larger tank; they can be territorial, so always monitor interactions.

Fun Fact: Angelfish are known for their intelligence and can recognize their owners.

7. Discus Fish (Symphysodon spp.)

Type: FreshwaterLifespan: 10 years
Tank Size: Minimum 50 gallons
Environment:

Temperature: 82-86°F (28-30°C)
pH Level: Soft, acidic water (6.0-7.0)
Hardness: Soft water

Care Needs:Discus are considered one of the most beautiful aquarium fish, known for their disc-shaped bodies and vivid colors. However, they have specific care needs and require stable, pristine water conditions to thrive. Discus prefer slightly warmer water, so maintaining a consistent temperature range is vital for their health.

Discus fish are more delicate than other species and require regular water changes to maintain excellent water quality. They should be fed a high-protein diet of live or frozen foods like brine shrimp, bloodworms, or specially formulated discus pellets. Due to their size and water needs, discus fish are best suited for more experienced aquarists.

How Many Per Tank: A school of 5 or more to reduce stress and display their beautiful colors.

Fun Fact: Discus fish are often referred to as the “king” of aquarium fish due to their beauty and demanding care requirements.

8. Oscar Fish (Astronotus ocellatus)

Type: FreshwaterLifespan: 10-15 years
Tank Size: Minimum 55 gallons
Environment:

Temperature: 75-80°F (24-27°C)
pH Level: Slightly acidic to neutral (6.0-7.5)
Hardness: Soft to moderately hard water

Care Needs:Oscars are large, intelligent, and sometimes aggressive fish that require a spacious tank and strong filtration. They are known for their curious nature and often recognize their owners. Oscars should be fed a varied diet, including pellets, flakes, and occasional live foods like worms, crickets, or fish.

Due to their size and strength, Oscars can be aggressive toward smaller fish or tankmates. They need a large tank with plenty of space to swim and are best kept alone or with other larger, peaceful fish.

How Many Per Tank: 1 Oscar per tank, as they can be aggressive with smaller species.

Fun Fact: Oscars are often referred to as “water dogs” because of their personality and ability to recognize their owners.

9. Platies (Xiphophorus maculatus)

Type: FreshwaterLifespan: 3-5 years
Tank Size: Minimum 10 gallons
Environment:

Temperature: 70-78°F (21-26°C)
pH Level: Slightly alkaline (7.0-8.0)
Hardness: Soft to moderately hard water

Care Needs:Platies are peaceful, hardy fish that come in a wide range of colors and patterns. They are livebearers, meaning they give birth to live young, so be prepared for baby platies unless you have all males or a separate breeding tank.

Platies are easy to care for and make great additions to community tanks. They are omnivores and will eat a variety of foods, including flakes, pellets, and occasional live food like daphnia or brine shrimp. Provide them with plenty of plants and swimming space, as they are active swimmers.

How Many Per Tank: 5 or more to maintain a school, with a 1 male to 2-3 female ratio to prevent excessive breeding.

Fun Fact: Platies are often found in a variety of colors, including red, yellow, and blue, thanks to selective breeding.

10. Rainbow Fish (Melanotaeniidae family)

Type: FreshwaterLifespan: 5-8 years
Tank Size: Minimum 30 gallons
Environment:

Temperature: 74-80°F (23-27°C)
pH Level: Slightly acidic to neutral (6.5-7.5)
Hardness: Soft to moderately hard water

Care Needs:Rainbow fish are vibrant, peaceful, and easy to care for. They are known for their beautiful, iridescent scales that shimmer under aquarium lights. These fish prefer to be kept in schools, which is necessary to bring out their full color potential. Rainbow fish do well in community tanks with other peaceful species and require plenty of plants and swimming space.

They are omnivores, so their diet can include high-quality flakes, pellets, and occasional live food. Regular water changes and good filtration are essential for maintaining their health.

How Many Per Tank: At least 6-8 rainbow fish to see their beautiful coloration and keep them social.

Fun Fact: Rainbow fish are named for their vibrant, multi-colored scales, which are most vivid when they are kept in schools.

Conclusion:

Caring for aquarium fish requires knowledge, patience, and attention to detail. By understanding the unique needs of each species, you can create a thriving, harmonious aquarium that both you and your fish will enjoy for years. Whether you’re a beginner or a seasoned aquarist, these top 10 fish provide a variety of colors, personalities, and care challenges to suit all skill levels.