28 Large Fish for Freshwater Aquariums

Keeping large freshwater fish requires a spacious tank, proper filtration, and a well-balanced diet. These fish need a clean, well-maintained environment and careful monitoring for health issues. With the right care, they can thrive and become a stunning addition to your aquarium.

1.Arowana (Including Silver Arowana)

Arowanas are highly sought-after large freshwater fish known for their impressive size and striking appearance. Their elongated, sleek bodies and metallic scales create a shimmering effect, while their graceful swimming motion captivates aquarists. The Silver Arowana is a particularly popular variant.

Care Requirements

• Fish Size:2–3 feet
• Tank Size: At least 250 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Live feeder fish, insects, shrimp, prawns, and carnivorous fish pellets.
• Behavior: Aggressive; suitable with large, robust fish only. Secure lid to prevent jumping.

2.Plecostomus (Pleco)

Plecostomus, commonly known as Plecos, are popular freshwater fish known for their algae-eating capabilities and unique appearance. They have armored bodies, sucker mouths, and a variety of patterns and colors. Plecos are a great addition to aquariums for keeping algae under control.

Care Requirements

• Fish Size:12–24 inches
• Tank Size: At least 75 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Algae, sinking pellets, and vegetables like zucchini and cucumber.
• Behavior: Generally peaceful but can be territorial with other Plecos. Provide hiding spots.

3.Jack Dempsey

Jack Dempsey fish are vibrant, hardy cichlids known for their striking coloration and robust nature. They are named after the famous boxer due to their aggressive behavior and territorial nature, making them a popular choice for experienced aquarists.

Care Requirements

• Fish Size: 7–8 inches
• Tank Size: At least 55 gallons.
• Temperature: 72°F to 86°F (22°C to 30°C).
• pH Level: 6.5 to 8.0.
• Diet: Omnivorous; eats pellets, flakes, live, and frozen foods.
• Behavior: Aggressive and territorial; best kept with similarly sized, robust fish. Provide plenty of hiding spots.

4.Flowerhorn Cichlid

Flowerhorn Cichlids are striking freshwater fish known for their vivid colors and distinctive head hump, or “kok.” They are a result of selective breeding and are popular for their unique appearance and energetic personality.

Care Requirements

• Fish Size: 10–14 inches
• Tank Size: At least 75 gallons.
• Temperature: 78°F to 84°F (25°C to 29°C).
• pH Level: 6.5 to 8.0.
• Diet: High-quality pellets, live and frozen foods, and vegetables.
• Behavior: Highly aggressive and territorial; best kept alone or with very large, robust tank mates.

5.Pacu

Pacu are large, peaceful freshwater fish related to piranhas but are primarily herbivorous. They are known 

for their human-like teeth and broad bodies, making them a unique and intriguing addition to large aquariums.

Care Requirements

• Fish Size:24–30 inches
• Tank Size: At least 150 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Primarily vegetables and fruits, supplemented with pellets and occasional proteins.
• Behavior: Generally peaceful but requires a large tank with ample swimming space and robust tank mates.

6.Redtail Catfish

Redtail Catfish are large, striking freshwater fish known for their vibrant red tails and powerful build. They are native to South America and are popular among aquarists who can accommodate their size and care needs.

Care Requirements

• Fish Size:24–36 inches
• Tank Size: At least 1,000 gallons (pond setups are often preferred).
• Temperature: 72°F to 79°F (22°C to 26°C).
• pH Level: 6.0 to 7.5.
• Diet: Carnivorous; feeds on fish, shrimp, pellets, and other meaty foods.
• Behavior: Predatory and territorial; best kept alone or with very large, compatible species.

7.Silver Dollar

Silver Dollar fish are peaceful, schooling freshwater fish known for their round, silver bodies that resemble coins. They are popular in community tanks due to their calm nature and attractive appearance.

Care Requirements

• Fish Size:6 inches
• Tank Size: At least 75 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 6.0 to 7.5.
• Diet: Herbivorous; prefers vegetables, fruits, and high-quality flakes or pellets.
• Behavior: Peaceful; best kept in schools of 5 or more. Compatible with other non-aggressive, similarly sized fish.

8.Green Terror

Green Terror cichlids are known for their striking iridescent blue-green coloration and aggressive behavior. They are a popular choice among experienced aquarists who appreciate their vibrant appearance and active nature.

Care Requirements

• Fish Size:6–12 inches
• Tank Size: At least 55 gallons.
• Temperature: 68°F to 77°F (20°C to 25°C).
• pH Level: 6.5 to 8.0.
• Diet: Omnivorous; eats pellets, flakes, live, and frozen foods.
• Behavior: Aggressive and territorial; best kept with similarly sized, robust fish. Provide plenty of hiding spots and territories to reduce aggression.

9.Severum Cichlid

Severum Cichlids are popular freshwater fish known for their attractive colors and relatively peaceful temperament compared to other cichlids. They are a great choice for medium to large community tanks.

Care Requirements

• Fish Size:6–8 inches
• Tank Size: At least 55 gallons.
• Temperature: 72°F to 84°F (22°C to 29°C).
• pH Level: 6.0 to 7.5.
• Diet: Omnivorous; eats pellets, flakes, vegetables, and live or frozen foods.
• Behavior: Generally peaceful but can be territorial; suitable for community tanks with similarly sized fish. Provide hiding spots and open swimming areas.

10.Giant Gourami

Giant Gouramis are large, hardy freshwater fish known for their intelligence and ability to recognize their owners. They have a unique, elongated body and can grow quite large, making them a standout in any aquarium.

Care Requirements

• Fish Size:12–14 inches
• Tank Size: At least 200 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.5 to 8.0.
• Diet: Omnivorous; eats pellets, flakes, vegetables, and live or frozen foods.
• Behavior: Generally peaceful but can become territorial; suitable for large tanks with similarly sized fish. Provide ample swimming space and some hiding spots.

11.Bala Shark

Bala Sharks are sleek, silver freshwater fish known for their active swimming behavior and peaceful nature. Despite their name, they are not true sharks but have a similar body shape.

Care Requirements

• Fish Size:12–14 inches
• Tank Size: At least 125 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.5 to 8.0.
• Diet: Omnivorous; eats pellets, flakes, vegetables, and live or frozen foods.
• Behavior: Peaceful; best kept in schools of 3 or more. Suitable for community tanks with similarly sized, non-aggressive fish.

12.Texas Cichlid

Texas Cichlids are large, colorful freshwater fish known for their striking appearance and territorial behavior. They are native to the rivers of Texas and northern Mexico, making them a unique addition to cichlid enthusiasts’ collections.

Care Requirements

• Fish Size:12–20 inches
• Tank Size: At least 75 gallons.
• Temperature: 68°F to 78°F (20°C to 26°C).
• pH Level: 6.5 to 8.0.
• Diet: Omnivorous; eats pellets, flakes, live, and frozen foods.
• Behavior: Aggressive and territorial; best kept with similarly sized, robust fish. Provide plenty of hiding spots and territories to reduce aggression.

13.Peacock Bass

Peacock Bass are large, predatory freshwater fish known for their vibrant coloration and impressive size. They are native to South America and are popular among experienced aquarists who can meet their care needs.

Care Requirements

• Fish Size:18–30 inches
• Tank Size: At least 200 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Carnivorous; feeds on fish, shrimp, and other meaty foods.
• Behavior: Predatory and territorial; best kept with very large, robust tank mates. Provide ample swimming space and hiding spots.

14.Black Ghost Knifefish

Black Ghost Knifefish are fascinating freshwater fish known for their unique body shape and nocturnal behavior. They have an elongated, ribbon-like body and can emit weak electric fields to navigate and communicate in their environment.

Care Requirements

• Fish Size:20 inches
• Tank Size: At least 100 gallons.
• Temperature: 73°F to 82°F (23°C to 28°C).
• pH Level: 6.0 to 8.0.
• Diet: Carnivorous; feeds on live and frozen foods such as bloodworms, brine shrimp, and small fish.
• Behavior: Generally peaceful but can be territorial with their own kind. Best kept with other peaceful, similarly sized fish. Provide plenty of hiding spots and subdued lighting.

15.Banded Leporinus

Banded Leporinus are striking freshwater fish known for their distinctive black and yellow vertical stripes. They are active swimmers and can add a splash of color to large community tanks.

Care Requirements

• Fish Size:6–8 inches
• Tank Size: At least 75 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.0 to 8.0.
• Diet: Omnivorous; eats vegetables, fruits, flakes, and pellets.
• Behavior: Generally peaceful but can be semi-aggressive; best kept with similarly sized, non-aggressive fish. Provide plenty of swimming space and hiding spots.

16.Goldfish

Goldfish are one of the most popular and recognizable freshwater fish, known for their bright colors and diverse varieties. They are hardy and can live for many years with proper care.

Care Requirements

• Fish Size:6–12 inches
• Tank Size: At least 20 gallons for a single goldfish; add 10 gallons for each additional goldfish.
• Temperature: 65°F to 75°F (18°C to 24°C).
• pH Level: 6.5 to 7.5.
• Diet: Omnivorous; eats flakes, pellets, vegetables, and occasional live or frozen foods.
• Behavior: Peaceful; suitable for community tanks with other peaceful, cold-water fish. Provide plenty of swimming space and regular water changes to maintain water quality.

17.Oscar

Oscars are large, intelligent freshwater fish known for their vibrant colors and strong personalities. They are popular among experienced aquarists due to their interactive nature and distinctive appearance.

Care Requirements

• Fish Size:10–14 inches
• Tank Size: At least 75 gallons for a single Oscar; larger tanks are needed for additional fish.
• Temperature: 74°F to 81°F (23°C to 27°C).
• pH Level: 6.0 to 8.0.
• Diet: Omnivorous; eats pellets, flakes, live and frozen foods, and vegetables.
• Behavior: Aggressive and territorial; best kept with similarly sized, robust fish. Provide hiding spots and open swimming areas. Regularly monitor water quality due to their high waste production.

18.Koi Fish

Koi fish are colorful, hardy freshwater fish commonly kept in outdoor ponds. They are known for their beautiful patterns and long lifespan, making them a favorite among pond enthusiasts.

Care Requirements

• Fish Size:12–36 inches
• Tank Size: Preferably kept in outdoor ponds of at least 1,000 gallons; indoor tanks should be at least 250 gallons.
• Temperature: 59°F to 77°F (15°C to 25°C).
• pH Level: 6.5 to 8.5.
• Diet: Omnivorous; eats pellets, vegetables, fruits, and occasional live or frozen foods.
• Behavior: Generally peaceful; best kept in groups. Provide a well-filtered, spacious environment with plenty of room to swim. Regularly monitor water quality and ensure proper aeration.

19.Suckermouth Catfish (Plecostomus)

Suckermouth Catfish, commonly known as Plecostomus or Plecos, are popular freshwater fish known for their algae-eating capabilities and unique appearance. They have armored bodies and a sucker mouth that helps them cling to surfaces.

Care Requirements

• Fish Size:12–24 inches
• Tank Size: At least 75 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Omnivorous; eats algae, sinking pellets, vegetables like zucchini and cucumber.
• Behavior: Generally peaceful but can be territorial with other Plecos. Provide hiding spots and plenty of surfaces for grazing.

20.Jaguar Cichlid

Jaguar Cichlids are large, predatory freshwater fish known for their striking spotted pattern and aggressive behavior. They are a popular choice for experienced aquarists who can provide the necessary care and environment.

Care Requirements

• Fish Size:12–15 inches
• Tank Size: At least 100 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 7.0 to 8.0.
• Diet: Carnivorous; eats live and frozen foods, pellets, and occasionally flakes.
• Behavior: Highly aggressive and territorial; best kept alone or with other large, robust fish. Provide plenty of hiding spots and open space for swimming. Regularly monitor water quality due to their high waste production.

21.Tiger Catfish

Tiger Catfish, also known as Tiger Shovelnose Catfish, are large, predatory freshwater fish known for their striking tiger-like stripes and elongated body. They are popular among aquarists who can accommodate their size and care needs.

Care Requirements

• Fish Size: 12–24 inches
• Tank Size: At least 200 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 6.0 to 7.5.
• Diet: Carnivorous; feeds on live and frozen foods, such as fish, shrimp, and meaty pellets.
• Behavior: Predatory and territorial; best kept alone or with other very large, compatible species. Provide ample swimming space, hiding spots, and ensure a secure tank cover.

22.Tire Track Eel

Tire Track Eels are unique freshwater fish known for their elongated bodies and distinctive tire track-like patterns. They are interesting and somewhat challenging additions to large aquariums.

Care Requirements

• Fish Size:24–36 inches
• Tank Size: At least 55 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.5 to 8.0.
• Diet: Carnivorous; feeds on live and frozen foods, such as bloodworms, brine shrimp, and small fish.
• Behavior: Generally peaceful but can be territorial with their own kind. Provide plenty of hiding spots, such as caves and dense vegetation. Ensure the tank has a secure lid to prevent escape.

23.Ornate Bichir

Ornate Bichirs are fascinating freshwater fish known for their prehistoric appearance and unique body structure. They have elongated bodies with a series of dorsal finlets and are often considered “living fossils.”

Care Requirements

• Fish Size:15–30 inches
• Tank Size: At least 75 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Carnivorous; feeds on live and frozen foods such as fish, shrimp, and worms.
• Behavior: Generally peaceful but can be predatory towards smaller fish. Best kept with similarly sized, robust tank mates. Provide plenty of hiding spots and ensure the tank has a secure lid to prevent escape.

24.Fahaka Puffer

Fahaka Puffers are large, charismatic freshwater fish known for their striking patterns and powerful beak-like teeth. They require special care and are best suited for experienced aquarists due to their unique needs and aggressive nature.

Care Requirements

• Fish Size:12–14 inches
• Tank Size: At least 100 gallons.
• Temperature: 75°F to 82°F (24°C to 28°C).
• pH Level: 7.0 to 8.0.
• Diet: Carnivorous; feeds on hard-shelled foods like snails, crayfish, and crustaceans to help wear down their constantly growing teeth.
• Behavior: Highly aggressive and territorial; best kept alone or with very large, robust tank mates. Provide ample hiding spots and open swimming space. Regularly monitor water quality and maintain a varied diet to ensure health.

25.Needle Nose Gar

Needle Nose Gars are distinctive freshwater fish known for their long, slender bodies and elongated snouts filled with sharp teeth. They are fascinating predators and require specific care to thrive in home aquariums.

Care Requirements

• Fish Size:12–36 inches
• Tank Size: At least 100 gallons.
• Temperature: 72°F to 82°F (22°C to 28°C).
• pH Level: 6.5 to 7.5.
• Diet: Carnivorous; feeds on live foods such as small fish, insects, and shrimp.
• Behavior: Predatory and semi-aggressive; best kept with similarly sized, robust tank mates. Provide plenty of open swimming space and some hiding spots. Ensure a secure lid to prevent escape.

Compatibility chart largest freshwater fish?

Here is the fish compatibility chart, with compatibility levels represented by a color scale. Each cell indicates the compatibility level between different fish species. The higher the number, the more compatible the fish are with each other. you can also reads 28 Small Aquarium Fish for Freshwater Tanks