Species › Bettas and gouramis

Betta tank mates and minimum tank size

Betta splendens

Bettas grow to 7 cm (2.8 in). Keep one per tank. They are usually best kept on their own. Their long fins draw fin nippers. They need 24.4–29.4 °C (76–85 °F) and pH 6.8–7.5.

Minimum tank

41 L (11 US gal), at least 45 cm (18 in) long

Adult size

7 cm (2.8 in)

Temperature

24.4–29.4 °C (76–85 °F)

pH

pH 6.8–7.5

Group

one per tank

Betta minimum tank size

Bettas need at least 41 L (11 US gal), in a tank at least 45 cm (18 in) long.

That is the largest minimum among the sources below. The planner also checks the tank length against the adult size of 7 cm (2.8 in): a tank shorter than 4 times that is cramped (28 cm (11 in)).

Betta tank mates

Each of the other 52 species in this reference, judged against bettas by the same rules as the compatibility checker. A guide, not a guarantee.

Compatible (1)

• Nerite snail

With care (29)

• AngelfishBettas are usually best kept alone. Some accept calm tank mates such as angelfish, many do not.
• Black neon tetraBettas are usually best kept alone. Some accept calm tank mates such as black neon tetras, many do not.
• Black skirt tetraThe only pH that suits both is pH 6.8–7.0, set by bettas and black skirt tetras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as black skirt tetras, many do not. Black skirt tetras nip fins, and bettas have long, trailing fins.
• Boeseman's rainbowfishBettas are usually best kept alone. Some accept calm tank mates such as Boeseman's rainbowfish, many do not.
• Bristlenose plecoBettas are usually best kept alone. Some accept calm tank mates such as bristlenose plecos, many do not.
• Bronze corydorasBettas are usually best kept alone. Some accept calm tank mates such as bronze corydoras, many do not.
• Celestial pearl danioBettas are usually best kept alone. Some accept calm tank mates such as celestial pearl danios, many do not. Celestial pearl danios (2.1 cm) are shy and easily intimidated by much larger bettas (7 cm).
• Cherry barbBettas are usually best kept alone. Some accept calm tank mates such as cherry barbs, many do not.
• Cherry shrimpBettas (7 cm) usually leave adult cherry shrimp (4 cm) alone but eat the young.
• Chili rasboraThe only pH that suits both is pH 6.8–7.0, set by bettas and chili rasboras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as chili rasboras, many do not.
• Common plecoBettas are usually best kept alone. Some accept calm tank mates such as common plecos, many do not.
• Congo tetraBettas are usually best kept alone. Some accept calm tank mates such as Congo tetras, many do not.
• DiscusThe only pH that suits both is pH 6.8–7.0, set by bettas and discus. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as discus, many do not.
• Ember tetraThe only pH that suits both is pH 6.8–7.0, set by bettas and ember tetras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as ember tetras, many do not. Ember tetras (2 cm) are shy and easily intimidated by much larger bettas (7 cm).
• Glass catfishThe only pH that suits both is pH 6.8–7.0, set by bettas and glass catfish. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as glass catfish, many do not.
• Glowlight tetraBettas are usually best kept alone. Some accept calm tank mates such as glowlight tetras, many do not.
• Harlequin rasboraThe only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and harlequin rasboras. That leaves no margin. The only pH that suits both is pH 6.8–7.0, set by bettas and harlequin rasboras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as harlequin rasboras, many do not.
• KribensisThe only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and kribensis. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as kribensis, many do not.
• Lemon tetraBettas are usually best kept alone. Some accept calm tank mates such as lemon tetras, many do not.
• MollyThe only pH that suits both is pH 7.5, set by mollies and bettas. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as mollies, many do not.
• Mystery snailThe only pH that suits both is pH 7.2–7.5, set by mystery snails and bettas. That leaves no margin. Mystery snails and bettas: only calm bettas leave its antennae alone.
• Neon tetraThe only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and neon tetras. That leaves no margin. The only pH that suits both is pH 6.8–7.0, set by bettas and neon tetras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as neon tetras, many do not.
• OtocinclusBettas are usually best kept alone. Some accept calm tank mates such as otocinclus, many do not.
• Panda corydorasThe only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and panda corydoras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as panda corydoras, many do not.
• PlatyThe only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and platies. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as platies, many do not.
• Pygmy corydorasBettas are usually best kept alone. Some accept calm tank mates such as pygmy corydoras, many do not.
• Red tail sharkBettas are usually best kept alone. Some accept calm tank mates such as red tail sharks, many do not.
• Siamese algae eaterBettas are usually best kept alone. Some accept calm tank mates such as Siamese algae eaters, many do not.
• SwordtailBettas are usually best kept alone. Some accept calm tank mates such as swordtails, many do not.

Not compatible (22)

• Cardinal tetraBettas need pH 6.8–7.5; cardinal tetras need pH 4.0–6.0. No pH suits both. Bettas are usually best kept alone. Some accept calm tank mates such as cardinal tetras, many do not.
• Clown loachClown loaches nip fins, and bettas have long, trailing fins. The only pH that suits both is pH 6.8–7.0, set by bettas and clown loaches. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as clown loaches, many do not.
• Cockatoo dwarf cichlidBettas need pH 6.8–7.5; cockatoo dwarf cichlids need pH 6.0. No pH suits both. The only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and cockatoo dwarf cichlids. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as cockatoo dwarf cichlids, many do not.
• Convict cichlidConvict cichlids are aggressive and best kept in a tank of their own; they attack fish several times their size, so bettas would be harassed. Bettas are usually best kept alone. Some accept calm tank mates such as convict cichlids, many do not.
• Dwarf gouramiBettas fight bettas, gouramis and paradise fish, and dwarf gouramis are one of them. Bettas are usually best kept alone. Some accept calm tank mates such as dwarf gouramis, many do not. Dwarf gouramis fight bettas, gouramis and paradise fish, and bettas are one of them.
• Endler's livebearerBettas and Endler's livebearers: a male betta treats bright, trailing-finned fish as rivals. Bettas are usually best kept alone. Some accept calm tank mates such as Endler's livebearers, many do not.
• German blue ramBettas need pH 6.8–7.5; German blue rams need pH 5.0–6.0. No pH suits both. Bettas are usually best kept alone. Some accept calm tank mates such as German blue rams, many do not.
• GoldfishBettas need 24.4–29.4 °C (76–85 °F); goldfish need 15.6–21.1 °C (60–70 °F). No temperature suits both. Bettas are usually best kept alone. Some accept calm tank mates such as goldfish, many do not.
• GuppyBettas and guppies: a male betta treats bright, trailing-finned fish as rivals. Bettas are usually best kept alone. Some accept calm tank mates such as guppies, many do not.
• Honey gouramiBettas fight bettas, gouramis and paradise fish, and honey gouramis are one of them. Bettas are usually best kept alone. Some accept calm tank mates such as honey gouramis, many do not.
• Kuhli loachBettas need pH 6.8–7.5; kuhli loaches need pH 5.5–6.5. No pH suits both. Bettas are usually best kept alone. Some accept calm tank mates such as kuhli loaches, many do not.
• OscarOscars grow to 46 cm and eat animals they can swallow; bettas grow to 7 cm. The only temperature that suits both is 24.4–25 °C (76–77 °F), set by bettas and oscars. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as oscars, many do not.
• Paradise fishBettas need 24.4–29.4 °C (76–85 °F); paradise fish need 16–22 °C (61–72 °F). No temperature suits both. Bettas fight bettas, gouramis and paradise fish, and paradise fish are one of them. Paradise fish fight bettas, gouramis and paradise fish, and bettas are one of them. Bettas are usually best kept alone. Some accept calm tank mates such as paradise fish, many do not.
• Pearl gouramiBettas fight bettas, gouramis and paradise fish, and pearl gouramis are one of them. Bettas are usually best kept alone. Some accept calm tank mates such as pearl gouramis, many do not.
• Peppered corydorasBettas need 24.4–29.4 °C (76–85 °F); peppered corydoras need 22–23 °C (72–73 °F). No temperature suits both. The only pH that suits both is pH 6.8–7.0, set by bettas and peppered corydoras. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as peppered corydoras, many do not.
• Rosy barbBettas need 24.4–29.4 °C (76–85 °F); rosy barbs need 18–22 °C (64–72 °F). No temperature suits both. Bettas are usually best kept alone. Some accept calm tank mates such as rosy barbs, many do not.
• Rummy-nose tetraBettas need pH 6.8–7.5; rummy-nose tetras need pH 5.5–6.0. No pH suits both. Bettas are usually best kept alone. Some accept calm tank mates such as rummy-nose tetras, many do not.
• Serpae tetraSerpae tetras nip fins, and bettas have long, trailing fins. Bettas are usually best kept alone. Some accept calm tank mates such as serpae tetras, many do not.
• Tiger barbTiger barbs nip fins, and bettas have long, trailing fins. Bettas are usually best kept alone. Some accept calm tank mates such as tiger barbs, many do not.
• White cloud mountain minnowBettas need 24.4–29.4 °C (76–85 °F); white cloud mountain minnows need 18–22 °C (64–72 °F). No temperature suits both. Bettas are usually best kept alone. Some accept calm tank mates such as white cloud mountain minnows, many do not.
• Yoyo loachYoyo loaches nip fins, and bettas have long, trailing fins. Bettas are usually best kept alone. Some accept calm tank mates such as yoyo loaches, many do not.
• Zebra danioBettas need 24.4–29.4 °C (76–85 °F); zebra danios need 18–24 °C (64–75 °F). No temperature suits both. Bettas are usually best kept alone. Some accept calm tank mates such as zebra danios, many do not.

Sources

Where sources differ, the value shown is computed as the most cautious one.

Behaviour notes are from Seriously Fish, read 2026-10-26.

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