Eastern Betta Tank Mates

Eastern Betta is semi-aggressive, so its tank mates need choosing with care. Here are the 47 freshwater species that pair well with an eastern betta — plus the 99 to avoid — with a live checker you can tune to your own tank.

By The Aquarium DB Team • Updated June 8, 2026 • Full Eastern Betta care guide →
Best matches

The best tank mates for an eastern betta

  • Assassin Snail ✅ Compatible
    Easy care · Peaceful · 3 cm · 22–26 °C (72–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Malaysian Trumpet Snail ✅ Compatible
    Easy care · Peaceful · 3 cm · 21–27 °C (70–81 °F)
    Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Axelrod's Cory ✅ Compatible
    Easy care · Peaceful · 5 cm · 23–28 °C (73–82 °F)
    Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Bandit Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 22–27 °C (72–81 °F)
    Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
  • Japanese Trapdoor Snail ✅ Compatible
    Easy care · Peaceful · 5 cm · 10–28 °C (50–82 °F)
    Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Julii Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 23–26 °C (73–79 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
  • Masked Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 22–28 °C (72–82 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Skunk Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 22–26 °C (72–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Rust Corydoras ✅ Compatible
    Easy care · Peaceful · 5.5 cm · 23–27 °C (73–81 °F)
    Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
  • Agassiz's Corydoras ✅ Compatible
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Elegant Cory ✅ Compatible
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • False Julii Corydoras ✅ Compatible
    Easy care · Peaceful · 6 cm · 22–26 °C (72–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Corydoras Catfish ✅ Compatible
    Easy care · Peaceful · 6.5 cm · 22–26 °C (72–79 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
  • Spotfin Corydoras ✅ Compatible
    Easy care · Peaceful · 6.5 cm · 22–26 °C (72–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Costa's Tetra ✅ Compatible
    Easy care · Peaceful · 7 cm · 22–28 °C (72–82 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Peppered Corydoras ✅ Compatible
    Easy care · Peaceful · 7 cm · 18–26 °C (64–79 °F)
    Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Spotted Corydoras ✅ Compatible
    Easy care · Peaceful · 7 cm · 22–27 °C (72–81 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
  • Gold Barb ✅ Compatible
    Easy care · Peaceful · 7.5 cm · 18–26 °C (64–79 °F)
    Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Black Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 8 cm · 23–28 °C (73–82 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Brilliant Rasbora ✅ Compatible
    Easy care · Peaceful · 9 cm · 22–28 °C (72–82 °F)
    Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Burmese Loach ✅ Compatible
    Easy care · Peaceful · 9 cm · 22–28 °C (72–82 °F)
    Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 10 cm · 24–30 °C (75–86 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Murray River Rainbowfish ✅ Compatible
    Easy care · Peaceful · 11 cm · 15–26 °C (59–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Giant Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 12 cm · 24–30 °C (75–86 °F)
    Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
With caution

Eastern Betta tank mates that can work with care

  • Afra Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 10 cm · 24–28 °C (75–82 °F)
    Different pH ranges (5.5–7 vs 7.8–8.6); doable if you sit in the shared band, but not ideal long-term.
  • African Butterfly Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 8 cm · 22–28 °C (72–82 °F)
    Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Agassiz's Dwarf Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 9 cm · 24–30 °C (75–86 °F)
    Eastern Betta and Agassiz's Dwarf Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
  • Amano Shrimp ⚠️ With caution
    Easy care · Peaceful · 5 cm · 18–28 °C (64–82 °F)
    Eastern Betta may eat Amano Shrimp or pick off its shrimplets — a densely planted tank with moss gives them a fighting chance.
  • Amapá Tetra ⚠️ With caution
    Medium care · Peaceful · 4 cm · 24–27 °C (75–81 °F)
    Expect Eastern Betta to harass Amapá Tetra at times; give dense cover and watch them at feeding.
  • Amazon Puffer ⚠️ With caution
    Medium care · Peaceful · 8 cm · 23–28 °C (73–82 °F)
    Your 75 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
  • Angelfish ⚠️ With caution
    Medium care · Semi-aggressive · 15 cm · 24–30 °C (75–86 °F)
    Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Ash Lipped Apisto ⚠️ With caution
    Hard care · Semi-aggressive · 7 cm · 24–29 °C (75–84 °F)
    Eastern Betta and Ash Lipped Apisto can both be territorial; doable with space and dense planting, but watch for chasing.

+ 186 more “with caution” pairings — see the interactive checker above.

Avoid

Fish to avoid keeping with an eastern betta

  • Wels Catfish ⛔ Avoid
    Hard care · Aggressive · 300 cm · 15–25 °C (59–77 °F)
    Two assertive fish, one genuinely aggressive: Eastern Betta and Wels Catfish will hold territory and clash.
  • Alligator Gar ⛔ Avoid
    Hard care · Aggressive · 250 cm · 24–28 °C (75–82 °F)
    Two assertive fish, one genuinely aggressive: Eastern Betta and Alligator Gar will hold territory and clash.
  • Redtail Catfish ⛔ Avoid
    Hard care · Aggressive · 120 cm · 24–27 °C (75–81 °F)
    Two assertive fish, one genuinely aggressive: Eastern Betta and Redtail Catfish will hold territory and clash.
  • Fire Eel ⛔ Avoid
    Medium care · Semi-aggressive · 100 cm · 24–28 °C (75–82 °F)
    Fire Eel (100 cm) is big enough to swallow the 6 cm Eastern Betta whole.
  • Clown Knifefish ⛔ Avoid
    Hard care · Aggressive · 90 cm · 24–28 °C (75–82 °F)
    Eastern Betta and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
  • Koi ⛔ Avoid
    Medium care · Peaceful · 90 cm · 4–28 °C (39–82 °F)
    Size gap is too large (90 vs 6 cm): Koi will treat Eastern Betta as food.
  • Spotted Gar ⛔ Avoid
    Hard care · Aggressive · 90 cm · 18–26 °C (64–79 °F)
    Two assertive fish, one genuinely aggressive: Eastern Betta and Spotted Gar will hold territory and clash.
  • Wolf Cichlid ⛔ Avoid
    Hard care · Aggressive · 72 cm · 24–30 °C (75–86 °F)
    Eastern Betta and Wolf Cichlid are both territorial and at least one is outright aggressive — expect serious fighting.

+ 91 more to avoid — the checker above flags every one.

Interactive tool

Check any fish against an eastern betta

Dial in your exact tank size and filter by result — the checker scores every species in our database against an eastern betta, with the reasoning for each verdict.

Tank-mate checker

Will it live with a Eastern Betta?

We compare each fish against your eastern betta on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.

  • Adolf's Cory✅ Compatible
    Peaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
    • Keep Adolf's Cory in a shoal of 6+ or it gets stressed and nippy.
  • Agassiz's Corydoras✅ Compatible
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Axelrod's Cory✅ Compatible
    Peaceful · 5 cm · Easy care · 23–28 °C (73–82 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
    • Keep Axelrod's Cory in a shoal of 6+ or it gets stressed and nippy.
  • Bandit Corydoras✅ Compatible
    Peaceful · 5 cm · Easy care · 22–27 °C (72–81 °F)
    • Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Bandit Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Blood Red Tiger Pleco✅ Compatible
    Peaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Butterfly Hillstream Loach✅ Compatible
    Peaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
    • Compatible on the things that matter: shared water near 24–24 °C, workable temperaments, and no predator-and-prey size gap.
  • Corydoras Catfish✅ Compatible
    Peaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
    • Keep Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
  • Costa's Tetra✅ Compatible
    Peaceful · 7 cm · Easy care · 22–28 °C (72–82 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
    • Keep Costa's Tetra in a shoal of 6+ or it gets stressed and nippy.
  • Duplicareus Corydoras✅ Compatible
    Peaceful · 5.5 cm · Medium care · 23–27 °C (73–81 °F)
    • Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Duplicareus Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Elegant Cory✅ Compatible
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
    • Keep Elegant Cory in a shoal of 6+ or it gets stressed and nippy.
  • False Julii Corydoras✅ Compatible
    Peaceful · 6 cm · Easy care · 22–26 °C (72–79 °F)
    • Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep False Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • German Blue Ram✅ Compatible
    Peaceful · 6 cm · Hard care · 27–30 °C (81–86 °F)
    • Compatible on the things that matter: shared water near 27–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Hillstream Loach✅ Compatible
    Peaceful · 6 cm · Hard care · 20–24 °C (68–75 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–24 °C — no size, zone or temperament conflicts.
  • Horseman Cory✅ Compatible
    Peaceful · 5 cm · Medium care · 22–26 °C (72–79 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
    • Keep Horseman Cory in a shoal of 6+ or it gets stressed and nippy.
  • Japanese Trapdoor Snail✅ Compatible
    Peaceful · 5 cm · Easy care · 10–28 °C (50–82 °F)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Narcissus II Cory✅ Compatible
    Peaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
    • Keep Narcissus II Cory in a shoal of 6+ or it gets stressed and nippy.
  • Peacock Gudgeon✅ Compatible
    Peaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Peppered Corydoras✅ Compatible
    Peaceful · 7 cm · Easy care · 18–26 °C (64–79 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
    • Keep Peppered Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Rio Negro Checkerboard Cichlid✅ Compatible
    Peaceful · 7 cm · Hard care · 24–29 °C (75–84 °F)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Rust Corydoras✅ Compatible
    Peaceful · 5.5 cm · Easy care · 23–27 °C (73–81 °F)
    • Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Rust Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Slate Corydoras✅ Compatible
    Peaceful · 6 cm · Medium care · 23–28 °C (73–82 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
    • Keep Slate Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Spotfin Corydoras✅ Compatible
    Peaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
    • Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Spotted Corydoras✅ Compatible
    Peaceful · 7 cm · Easy care · 22–27 °C (72–81 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
    • Keep Spotted Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Sterbai Corydoras✅ Compatible
    Peaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
    • Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Black Ruby Barb⚠️ With caution
    Semi-aggressive · 6 cm · Easy care · 22–26 °C (72–79 °F)
    • Eastern Betta and Black Ruby Barb can both be territorial; doable with space and dense planting, but watch for chasing.
    • Your 75 L tank is below the ~100 L this pairing really wants — crowding raises aggression.
    • Keep Black Ruby Barb in a shoal of 6+ or it gets stressed and nippy.
  • Black Skirt Tetra⚠️ With caution
    Semi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
    • Eastern Betta and Black Skirt Tetra can both be territorial; doable with space and dense planting, but watch for chasing.
    • Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
  • Blackline Rasbora⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Expect Eastern Betta to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
    • Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Desert Goby⚠️ With caution
    Semi-aggressive · 6 cm · Easy care · 18–28 °C (64–82 °F)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Diamond Tetra⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Eastern Betta is semi-aggressive and may chase or nip the smaller Diamond Tetra — plant heavily and break up sight lines.
    • Keep Diamond Tetra in a shoal of 6+ or it gets stressed and nippy.
  • Dwarf Chain Loach⚠️ With caution
    Peaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
    • Keep Dwarf Chain Loach in a shoal of 6+ or it gets stressed and nippy.
  • Glass Bloodfin Tetra⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Eastern Betta is semi-aggressive and may chase or nip the smaller Glass Bloodfin Tetra — plant heavily and break up sight lines.
    • Keep Glass Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
  • GloFish Tetra⚠️ With caution
    Semi-aggressive · 6 cm · Easy care · 21–28 °C (70–82 °F)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
    • Keep GloFish Tetra in a shoal of 6+ or it gets stressed and nippy.
  • Guppy⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Eastern Betta and Guppy are close in size, but the semi-aggressive one tends to dominate — add guppy in a group to spread the pressure.
  • Neon Dwarf Rainbowfish⚠️ With caution
    Peaceful · 6 cm · Easy care · 23–27 °C (73–81 °F)
    • Eastern Betta and Neon Dwarf Rainbowfish are close in size, but the semi-aggressive one tends to dominate — add neon dwarf rainbowfish in a group to spread the pressure.
    • Keep Neon Dwarf Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
  • Odessa Barb⚠️ With caution
    Semi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
    • Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
  • Peaceful Betta⚠️ With caution
    Semi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
    • Eastern Betta and Peaceful Betta can both be territorial; doable with space and dense planting, but watch for chasing.
    • Eastern Betta and Peaceful Betta are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
  • Pearl Danio⚠️ With caution
    Peaceful · 6 cm · Easy care · 20–25 °C (68–77 °F)
    • Eastern Betta and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
    • Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
  • Platy⚠️ With caution
    Peaceful · 6 cm · Easy care · 21–28 °C (70–82 °F)
    • One likes softer water and the other harder (1–8 vs 10–28 dGH) — a compromise, not a perfect match.
    • Expect Eastern Betta to harass Platy at times; give dense cover and watch them at feeding.
  • Samurai Gourami⚠️ With caution
    Peaceful · 6 cm · Hard care · 24–28 °C (75–82 °F)
    • Eastern Betta and Samurai Gourami are close in size, but the semi-aggressive one tends to dominate — add samurai gourami in a group to spread the pressure.
    • Eastern Betta and Samurai Gourami are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
  • Three-striped Dwarf Cichlid⚠️ With caution
    Semi-aggressive · 6 cm · Medium care · 23–29 °C (73–84 °F)
    • Eastern Betta and Three-striped Dwarf Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
  • Alligator Gar⛔ Not recommended
    Aggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
    • Two assertive fish, one genuinely aggressive: Eastern Betta and Alligator Gar will hold territory and clash.
    • Size gap is too large (250 vs 6 cm): Alligator Gar will treat Eastern Betta as food.
    • Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
  • Clown Knifefish⛔ Not recommended
    Aggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
    • Eastern Betta and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Size gap is too large (90 vs 6 cm): Clown Knifefish will treat Eastern Betta as food.
    • Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
  • Fire Eel⛔ Not recommended
    Semi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
    • Fire Eel (100 cm) is big enough to swallow the 6 cm Eastern Betta whole.
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
    • Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
  • Koi⛔ Not recommended
    Peaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
    • Size gap is too large (90 vs 6 cm): Koi will treat Eastern Betta as food.
    • Water hardness preferences differ (Eastern Betta 1–8 vs Koi 9–18 dGH).
    • Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
  • Redtail Catfish⛔ Not recommended
    Aggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
    • Two assertive fish, one genuinely aggressive: Eastern Betta and Redtail Catfish will hold territory and clash.
    • Size gap is too large (120 vs 6 cm): Redtail Catfish will treat Eastern Betta as food.
    • Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
  • Spotted Gar⛔ Not recommended
    Aggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
    • Two assertive fish, one genuinely aggressive: Eastern Betta and Spotted Gar will hold territory and clash.
    • Eastern Betta is bite-sized to a 90 cm predatory spotted gar — it will be eaten.
    • Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
  • Wels Catfish⛔ Not recommended
    Aggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
    • Two assertive fish, one genuinely aggressive: Eastern Betta and Wels Catfish will hold territory and clash.
    • Eastern Betta is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
    • Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
  • Wolf Cichlid⛔ Not recommended
    Aggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
    • Eastern Betta and Wolf Cichlid are both territorial and at least one is outright aggressive — expect serious fighting.
    • Eastern Betta is bite-sized to a 72 cm predatory wolf cichlid — it will be eaten.
    • Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.

Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.

Setting up an eastern betta community tank

Give the group a stable, planted 75 L+ tank with a gentle filter, a reliable heater and plenty of cover — broken sight lines and hiding spots let mid-water and bottom dwellers keep out of each other's way. Cycle it fully and stock gradually.

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How to choose

How to choose the right tank mates for an eastern betta

Being semi-aggressive, eastern betta can nip or harass smaller, slower or long-finned fish — give it space, broken sight-lines and similarly robust companions. It mostly occupies the top of the tank, so it pairs naturally with species that use the other levels.

Eastern Betta grows to about 6 cm, so avoid tank mates small enough to be seen as food — as a rule of thumb, skip anything under roughly 3 cm. Match its water, too: aim for 24–28 °C (75–82 °F), pH 5.5–7 and 1–8 dGH. Fish needing very different conditions — coldwater species, or hard-water lovers against a soft-water fish — rarely thrive side by side.

Eastern Betta doesn't need its own kind to feel secure; think twice before keeping more than one if it is territorial. Whatever you add, introduce new fish slowly, watch for bullying in the first days, and have a backup plan if temperaments clash.

FAQ

Frequently asked questions

Can an eastern betta live with other fish?

Yes — with the right companions. Our checker finds 47 compatible freshwater species for eastern betta. Pick calm, similarly-sized fish that share its water needs and add them to a mature, well-planted tank.

What is the best tank mate for an eastern betta?

Easy, peaceful, similarly-sized species top the list — for example Assassin Snail, Malaysian Trumpet Snail, Axelrod's Cory. Use the checker above to match against your own tank size.

What fish should you avoid keeping with an eastern betta?

Avoid Wels Catfish, Alligator Gar, Redtail Catfish and similar — usually a temperature, size or temperament clash. The full "avoid" list below gives the reason for each.

How big a tank do eastern betta tank mates need?

Start from Eastern Betta's own minimum and scale up with every addition. The checker above defaults to a 75 L community tank and flags pairings that need more room — drag the slider to match your setup.

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