Mahachai Betta Tank Mates

Mahachai Betta is aggressive, so its tank mates need choosing with care. Here are the 45 freshwater species that pair well with a mahachai betta — plus the 181 to avoid — with a live checker you can tune to your own tank.

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

The best tank mates for a mahachai betta

  • Assassin Snail ✅ Compatible
    Easy care · Peaceful · 3 cm · 22–26 °C (72–79 °F)
    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)
    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)
    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)
    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)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Masked Corydoras ✅ Compatible
    Easy care · Peaceful · 5 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.
  • Skunk Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 22–26 °C (72–79 °F)
    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)
    Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Elegant Cory ✅ Compatible
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    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)
    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)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Spotfin Corydoras ✅ Compatible
    Easy care · Peaceful · 6.5 cm · 22–26 °C (72–79 °F)
    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.
  • Peppered Corydoras ✅ Compatible
    Easy care · Peaceful · 7 cm · 18–26 °C (64–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Spotted Corydoras ✅ Compatible
    Easy care · Peaceful · 7 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.
  • Gold Barb ✅ Compatible
    Easy care · Peaceful · 7.5 cm · 18–26 °C (64–79 °F)
    Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Black Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 8 cm · 23–28 °C (73–82 °F)
    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)
    Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–30 °C — no size, zone or temperament conflicts.
  • 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)
    Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
  • Giant Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 12 cm · 24–30 °C (75–86 °F)
    Compatible on the things that matter: shared water near 24–30 °C, workable temperaments, and no predator-and-prey size gap.
With caution

Mahachai Betta tank mates that can work with care

  • African Dwarf Frog ⚠️ With caution
    Medium care · Peaceful · 4 cm · 22–26 °C (72–79 °F)
    Watch for Mahachai Betta picking off any african dwarf frog small enough to fit in its mouth.
  • Amano Shrimp ⚠️ With caution
    Easy care · Peaceful · 5 cm · 18–28 °C (64–82 °F)
    Mahachai 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 Mahachai 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.
  • Bearded Corydoras ⚠️ With caution
    Medium care · Peaceful · 10 cm · 18–24 °C (64–75 °F)
    Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Black Phantom Tetra ⚠️ With caution
    Easy care · Peaceful · 4.5 cm · 22–28 °C (72–82 °F)
    Expect Mahachai Betta to harass Black Phantom Tetra at times; give dense cover and watch them at feeding.
  • Blackline Rasbora ⚠️ With caution
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    Expect Mahachai Betta to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
  • Blackwing Hatchetfish ⚠️ With caution
    Medium care · Peaceful · 3.5 cm · 23–28 °C (73–82 °F)
    Expect Mahachai Betta to harass Blackwing Hatchetfish at times; give dense cover and watch them at feeding.

+ 106 more “with caution” pairings — see the interactive checker above.

Avoid

Fish to avoid keeping with a mahachai betta

  • Mekong Giant Catfish ⛔ Avoid
    Hard care · Semi-aggressive · 300 cm · 20–28 °C (68–82 °F)
    Two assertive fish, one genuinely aggressive: Mahachai Betta and Mekong Giant Catfish will hold territory and clash.
  • Wels Catfish ⛔ Avoid
    Hard care · Aggressive · 300 cm · 15–25 °C (59–77 °F)
    Two assertive fish, one genuinely aggressive: Mahachai 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: Mahachai 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: Mahachai Betta and Redtail Catfish will hold territory and clash.
  • Fire Eel ⛔ Avoid
    Medium care · Semi-aggressive · 100 cm · 24–28 °C (75–82 °F)
    Mahachai Betta and Fire Eel are both territorial and at least one is outright aggressive — expect serious fighting.
  • Clown Knifefish ⛔ Avoid
    Hard care · Aggressive · 90 cm · 24–28 °C (75–82 °F)
    Mahachai 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 7 cm): Koi will treat Mahachai Betta as food.
  • Spotted Gar ⛔ Avoid
    Hard care · Aggressive · 90 cm · 18–26 °C (64–79 °F)
    Two assertive fish, one genuinely aggressive: Mahachai Betta and Spotted Gar will hold territory and clash.

+ 173 more to avoid — the checker above flags every one.

Interactive tool

Check any fish against a mahachai betta

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

Tank-mate checker

Will it live with a Mahachai Betta?

We compare each fish against your mahachai 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)
    • 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)
    • Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
    • Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Bamboo Shrimp✅ Compatible
    Peaceful · 8 cm · Medium care · 22–27 °C (72–81 °F)
    • 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
    Peaceful · 8 cm · Easy care · 23–28 °C (73–82 °F)
    • Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Blood Red Tiger Pleco✅ Compatible
    Peaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
    • 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.
  • Bolivian Ram✅ Compatible
    Peaceful · 8 cm · Medium care · 24–28 °C (75–82 °F)
    • 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
    Peaceful · 9 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 Brilliant Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Burmese Loach✅ Compatible
    Peaceful · 9 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.
  • 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)
    • Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Corydoras Catfish 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)
    • 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 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)
    • 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)
    • 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 27–30 °C, workable temperaments, and no predator-and-prey size gap.
  • Gold Barb✅ Compatible
    Peaceful · 7.5 cm · Easy care · 18–26 °C (64–79 °F)
    • Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Gold Barb in a shoal of 6+ or it gets stressed and nippy.
  • 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)
    • 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.
  • Peppered Corydoras✅ Compatible
    Peaceful · 7 cm · Easy care · 18–26 °C (64–79 °F)
    • Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Peppered Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • 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)
    • 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.
  • Splashing Tetra✅ Compatible
    Peaceful · 8 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.
    • Both favour the top of the tank — offer enough cover so they aren't always in each other's space.
    • Keep Splashing Tetra 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)
    • 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 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)
    • Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
    • 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)
    • Compatible on the things that matter: shared water near 24–30 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Amazon Puffer⚠️ With caution
    Peaceful · 8 cm · Medium care · 23–28 °C (73–82 °F)
    • Your 75 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
    • Keep Amazon Puffer 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 Mahachai 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.
  • Bright Diamond Tetra⚠️ With caution
    Peaceful · 7 cm · Hard care · 24–28 °C (75–82 °F)
    • Expect Mahachai Betta to harass Bright Diamond Tetra at times; give dense cover and watch them at feeding.
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
    • Keep Bright Diamond Tetra in a shoal of 8+ or it gets stressed and nippy.
  • Celebes Rainbowfish⚠️ With caution
    Peaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
    • Mahachai Betta is aggressive and may chase or nip the smaller Celebes Rainbowfish — plant heavily and break up sight lines.
    • Keep Celebes Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
  • Congo Tetra⚠️ With caution
    Peaceful · 8 cm · Medium care · 22–28 °C (72–82 °F)
    • Your 75 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
    • Keep Congo Tetra in a shoal of 6+ or it gets stressed and nippy.
  • Costa's Tetra⚠️ With caution
    Peaceful · 7 cm · Easy care · 22–28 °C (72–82 °F)
    • Expect Mahachai Betta to harass Costa's Tetra at times; give dense cover and watch them at feeding.
    • Keep Costa's Tetra in a shoal of 6+ or it gets stressed and nippy.
  • Croaking Gourami⚠️ With caution
    Peaceful · 7 cm · Easy care · 24–28 °C (75–82 °F)
    • Mahachai Betta is aggressive and may chase or nip the smaller Croaking Gourami — plant heavily and break up sight lines.
    • Mahachai Betta and Croaking Gourami are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
  • Diamond Tetra⚠️ With caution
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Expect Mahachai 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.
  • Glass Catfish⚠️ With caution
    Peaceful · 8 cm · Medium care · 23–28 °C (73–82 °F)
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
    • Keep Glass Catfish in a shoal of 6+ or it gets stressed and nippy.
  • Melon Barb⚠️ With caution
    Peaceful · 7 cm · Easy care · 22–28 °C (72–82 °F)
    • Mahachai Betta and Melon Barb are close in size, but the aggressive one tends to dominate — add melon barb in a group to spread the pressure.
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
    • Keep Melon Barb in a shoal of 8+ or it gets stressed and nippy.
  • Pantanal Corydoras⚠️ With caution
    Peaceful · 8 cm · Medium care · 22–27 °C (72–81 °F)
    • Your 75 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
    • Keep Pantanal Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Peacock Gudgeon⚠️ With caution
    Peaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
    • Mahachai Betta and Peacock Gudgeon are close in size, but the aggressive one tends to dominate — add peacock gudgeon in a group to spread the pressure.
  • Rio Negro Checkerboard Cichlid⚠️ With caution
    Peaceful · 7 cm · Hard care · 24–29 °C (75–84 °F)
    • Water hardness preferences differ (Mahachai Betta 5–20 vs Rio Negro Checkerboard Cichlid 0–4 dGH).
  • Rounded Filament Barb⚠️ With caution
    Peaceful · 7 cm · Medium care · 22–27 °C (72–81 °F)
    • Mahachai Betta is aggressive and may chase or nip the smaller Rounded Filament Barb — plant heavily and break up sight lines.
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
    • Keep Rounded Filament Barb in a shoal of 6+ or it gets stressed and nippy.
  • Scissortail Rasbora⚠️ With caution
    Peaceful · 8 cm · Easy care · 22–27 °C (72–81 °F)
    • Your 75 L tank is below the ~90 L this pairing really wants — crowding raises aggression.
    • Keep Scissortail Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Alligator Gar⛔ Not recommended
    Aggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
    • Two assertive fish, one genuinely aggressive: Mahachai Betta and Alligator Gar will hold territory and clash.
    • Size gap is too large (250 vs 7 cm): Alligator Gar will treat Mahachai 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)
    • Mahachai Betta and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Size gap is too large (90 vs 7 cm): Clown Knifefish will treat Mahachai 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)
    • Mahachai Betta and Fire Eel are both territorial and at least one is outright aggressive — expect serious fighting.
    • Size gap is too large (100 vs 7 cm): Fire Eel will treat Mahachai Betta as food.
    • 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 7 cm): Koi will treat Mahachai Betta as food.
    • Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
  • Mekong Giant Catfish⛔ Not recommended
    Semi-aggressive · 300 cm · Hard care · 20–28 °C (68–82 °F)
    • Two assertive fish, one genuinely aggressive: Mahachai Betta and Mekong Giant Catfish will hold territory and clash.
    • Your 75 L tank is below the ~100000 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: Mahachai Betta and Redtail Catfish will hold territory and clash.
    • Redtail Catfish (120 cm) is big enough to swallow the 7 cm Mahachai Betta whole.
    • 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: Mahachai Betta and Spotted Gar will hold territory and clash.
    • Mahachai 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: Mahachai Betta and Wels Catfish will hold territory and clash.
    • Mahachai 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.

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 mahachai 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 mahachai betta

Mahachai Betta is aggressive and territorial, so most community fish are unsafe; any tank mate must be large, tough and able to hold its own. It mostly occupies the top of the tank, so it pairs naturally with species that use the other levels.

Mahachai Betta grows to about 7 cm, so avoid tank mates small enough to be seen as food — as a rule of thumb, skip anything under roughly 4 cm. Match its water, too: aim for 24–30 °C (75–86 °F), pH 6.5–8 and 5–20 dGH. Fish needing very different conditions — coldwater species, or hard-water lovers against a soft-water fish — rarely thrive side by side.

Mahachai 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 mahachai betta live with other fish?

Yes — with the right companions. Our checker finds 45 compatible freshwater species for mahachai 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 mahachai 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 mahachai betta?

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

How big a tank do mahachai betta tank mates need?

Start from Mahachai 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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