Peaceful Betta Tank Mates

Peaceful Betta is semi-aggressive, so its tank mates need choosing with care. Here are the 50 freshwater species that pair well with a peaceful 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 Peaceful Betta care guide →
Best matches

The best tank mates for a peaceful betta

  • Assassin Snail ✅ Compatible
    Easy care · Peaceful · 3 cm · 22–26 °C (72–79 °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.
  • Malaysian Trumpet Snail ✅ Compatible
    Easy care · Peaceful · 3 cm · 21–27 °C (70–81 °F)
    Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
  • 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)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Skunk Corydoras ✅ Compatible
    Easy care · Peaceful · 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.
  • 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)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
  • 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, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
  • Spotted Corydoras ✅ Compatible
    Easy care · Peaceful · 7 cm · 22–27 °C (72–81 °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.
  • 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Brilliant Rasbora ✅ Compatible
    Easy care · Peaceful · 9 cm · 22–28 °C (72–82 °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.
  • Burmese Loach ✅ Compatible
    Easy care · Peaceful · 9 cm · 22–28 °C (72–82 °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.
  • Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 10 cm · 24–30 °C (75–86 °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.
  • Molly ✅ Compatible
    Easy care · Peaceful · 10 cm · 23–28 °C (73–82 °F)
    Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • 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.
With caution

Peaceful Betta tank mates that can work with care

  • Afra Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 10 cm · 24–28 °C (75–82 °F)
    pH preferences only just meet (Peaceful Betta 5.5–7.5 vs Afra Cichlid 7.8–8.6) — target the overlap and acclimate slowly.
  • African Butterfly Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 8 cm · 22–28 °C (72–82 °F)
    Peaceful Betta and African Butterfly Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
  • Agassiz's Dwarf Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 9 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.
  • Amano Shrimp ⚠️ With caution
    Easy care · Peaceful · 5 cm · 18–28 °C (64–82 °F)
    Adult Amano Shrimp might survive with Peaceful Betta, but expect the young to be eaten — plant heavily.
  • Amapá Tetra ⚠️ With caution
    Medium care · Peaceful · 4 cm · 24–27 °C (75–81 °F)
    Peaceful Betta is semi-aggressive and may chase or nip the smaller Amapá Tetra — plant heavily and break up sight lines.
  • 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)
    Peaceful Betta and Angelfish can both be territorial; doable with space and dense planting, but watch for chasing.
  • Ash Lipped Apisto ⚠️ With caution
    Hard care · Semi-aggressive · 7 cm · 24–29 °C (75–84 °F)
    Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.

+ 183 more “with caution” pairings — see the interactive checker above.

Avoid

Fish to avoid keeping with a peaceful betta

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

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

Interactive tool

Check any fish against a peaceful betta

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

Tank-mate checker

Will it live with a Peaceful Betta?

We compare each fish against your peaceful 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
    • 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)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Blue Turbo Snail✅ Compatible
    Peaceful · 5 cm · Medium care · 25–30 °C (77–86 °F)
    • Compatible on the things that matter: shared water near 25–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Butterfly Hillstream Loach✅ Compatible
    Peaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–24 °C — no size, zone or temperament conflicts.
  • Celebes Rainbowfish✅ Compatible
    Peaceful · 7 cm · Medium care · 22–28 °C (72–82 °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 Celebes Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
  • 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)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
    • 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)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
    • 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)
    • Compatible on the things that matter: shared water near 24–24 °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, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
    • 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)
    • 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.
  • 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)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
    • 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
    • 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
    • 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)
    • 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 ~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)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
    • 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 Peaceful 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)
    • Peaceful Betta and Desert Goby can both be territorial; doable with space and dense planting, but watch for chasing.
  • Diamond Tetra⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Expect Peaceful Betta to harass Diamond Tetra at times; give dense cover and watch them at feeding.
    • 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.
  • Eastern Betta⚠️ With caution
    Semi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
    • Peaceful Betta and Eastern Betta can both be territorial; doable with space and dense planting, but watch for chasing.
    • Peaceful Betta and Eastern Betta are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
  • Glass Bloodfin Tetra⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Expect Peaceful Betta to harass Glass Bloodfin Tetra at times; give dense cover and watch them at feeding.
    • 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)
    • Peaceful Betta and GloFish Tetra can both be territorial; doable with space and dense planting, but watch for chasing.
    • 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)
    • Expect Peaceful Betta to harass Guppy at times; give dense cover and watch them at feeding.
  • Neon Dwarf Rainbowfish⚠️ With caution
    Peaceful · 6 cm · Easy care · 23–27 °C (73–81 °F)
    • Peaceful Betta is semi-aggressive and may chase or nip the smaller Neon Dwarf Rainbowfish — plant heavily and break up sight lines.
    • 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)
    • Peaceful Betta and Odessa Barb can both be territorial; doable with space and dense planting, but watch for chasing.
    • Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
  • Pearl Danio⚠️ With caution
    Peaceful · 6 cm · Easy care · 20–25 °C (68–77 °F)
    • Peaceful Betta is semi-aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
    • 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)
    • Peaceful Betta and Platy are close in size, but the semi-aggressive one tends to dominate — add platy in a group to spread the pressure.
  • Samurai Gourami⚠️ With caution
    Peaceful · 6 cm · Hard care · 24–28 °C (75–82 °F)
    • Expect Peaceful Betta to harass Samurai Gourami at times; give dense cover and watch them at feeding.
    • Peaceful 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)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Alligator Gar⛔ Not recommended
    Aggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
    • Peaceful Betta and Alligator Gar are both territorial and at least one is outright aggressive — expect serious fighting.
    • Size gap is too large (250 vs 6 cm): Alligator Gar will treat Peaceful 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)
    • Two assertive fish, one genuinely aggressive: Peaceful Betta and Clown Knifefish will hold territory and clash.
    • Size gap is too large (90 vs 6 cm): Clown Knifefish will treat Peaceful 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)
    • Size gap is too large (100 vs 6 cm): Fire Eel will treat Peaceful Betta as food.
    • Peaceful Betta and Fire Eel can both be territorial; doable with space and dense planting, but watch for chasing.
    • 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)
    • Peaceful Betta is bite-sized to a 90 cm koi — it will be eaten.
    • 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)
    • Peaceful Betta and Redtail Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Size gap is too large (120 vs 6 cm): Redtail Catfish will treat Peaceful 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)
    • Peaceful Betta and Spotted Gar are both territorial and at least one is outright aggressive — expect serious fighting.
    • Size gap is too large (90 vs 6 cm): Spotted Gar will treat Peaceful Betta as food.
    • 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)
    • Peaceful Betta and Wels Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Wels Catfish (300 cm) is big enough to swallow the 6 cm Peaceful Betta whole.
    • 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)
    • Two assertive fish, one genuinely aggressive: Peaceful Betta and Wolf Cichlid will hold territory and clash.
    • Size gap is too large (72 vs 6 cm): Wolf Cichlid will treat Peaceful Betta as food.
    • 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 a peaceful 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 a peaceful betta

Being semi-aggressive, peaceful 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.

Peaceful 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 5.5–7.5 and 1–10 dGH. Fish needing very different conditions — coldwater species, or hard-water lovers against a soft-water fish — rarely thrive side by side.

Peaceful 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 a peaceful betta live with other fish?

Yes — with the right companions. Our checker finds 50 compatible freshwater species for peaceful 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 a peaceful 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 a peaceful 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 peaceful betta tank mates need?

Start from Peaceful 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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