Discus Tank Mates

• Angelfish✅ Compatible
  Semi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Arrowhead Puffer✅ Compatible
  Aggressive · 12 cm · Hard care · 23–28 °C (73–82 °F)
  • Compatible on the things that matter: shared water near 28–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Banded Gourami✅ Compatible
  Semi-aggressive · 12 cm · Easy care · 22–28 °C (72–82 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Blue Gourami✅ Compatible
  Semi-aggressive · 13 cm · Easy care · 22–28 °C (72–82 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 28–28 °C — no size, zone or temperament conflicts.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Bristlenose Pleco✅ Compatible
  Peaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Cupid Cichlid✅ Compatible
  Semi-aggressive · 12 cm · Medium care · 24–29 °C (75–84 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Electric Blue Acara✅ Compatible
  Semi-aggressive · 16 cm · Medium care · 22–28 °C (72–82 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 28–28 °C — no size, zone or temperament conflicts.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Firemouth Cichlid✅ Compatible
  Semi-aggressive · 15 cm · Medium care · 22–29 °C (72–84 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Giant Betta✅ Compatible
  Peaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
  • Compatible on the things that matter: shared water near 28–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Giant Kuhli Loach✅ Compatible
  Peaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
  • Both are peaceful, and their water overlaps around 28–30 °C — no size, zone or temperament conflicts.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Gold Zebra Loach✅ Compatible
  Semi-aggressive · 15 cm · Medium care · 25–29 °C (77–84 °F)
  • Compatible on the things that matter: shared water near 28–29 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Green Phantom Pleco✅ Compatible
  Semi-aggressive · 15 cm · Medium care · 26–30 °C (79–86 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 28–30 °C — no size, zone or temperament conflicts.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Guyana Flag Cichlid✅ Compatible
  Semi-aggressive · 18 cm · Medium care · 24–30 °C (75–86 °F)
  • Compatible on the things that matter: shared water near 28–30 °C, workable temperaments, and no predator-and-prey size gap.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Marbled Hoplo✅ Compatible
  Peaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
  • Both are peaceful, and their water overlaps around 28–28 °C — no size, zone or temperament conflicts.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Medusa Pleco✅ Compatible
  Peaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Moonlight Gourami✅ Compatible
  Peaceful · 15 cm · Easy care · 25–30 °C (77–86 °F)
  • Compatible on the things that matter: shared water near 28–30 °C, workable temperaments, and no predator-and-prey size gap.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Panama Convict Cichlid✅ Compatible
  Aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
  • Compatible on the things that matter: shared water near 28–30 °C, workable temperaments, and no predator-and-prey size gap.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Pearl Gourami✅ Compatible
  Peaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Polka-dot Loach✅ Compatible
  Semi-aggressive · 13 cm · Medium care · 24–28 °C (75–82 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Rainbow Cichlid✅ Compatible
  Semi-aggressive · 14 cm · Easy care · 22–28 °C (72–82 °F)
  • Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 28–28 °C — no size, zone or temperament conflicts.
  • Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Snowball Pleco✅ Compatible
  Peaceful · 16 cm · Medium care · 24–30 °C (75–86 °F)
  • Compatible on the things that matter: shared water near 28–30 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Striped Eel Loach✅ Compatible
  Peaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
  • Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• T-bar Cichlid✅ Compatible
  Semi-aggressive · 12 cm · Medium care · 22–28 °C (72–82 °F)
  • Compatible on the things that matter: shared water near 28–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Yoyo Loach✅ Compatible
  Semi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
  • Compatible on the things that matter: shared water near 28–30 °C, workable temperaments, and no predator-and-prey size gap.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Altifrons Geophagus⚠️ With caution
  Semi-aggressive · 25 cm · Medium care · 24–28 °C (75–82 °F)
  • Altifrons Geophagus and Discus are close in size, but the semi-aggressive one tends to dominate — add discus in a group to spread the pressure.
  • Your 200 L tank is below the ~378 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
  • Keep Altifrons Geophagus in a shoal of 6+ or it gets stressed and nippy.
• Blackcheek Cichlid⚠️ With caution
  Aggressive · 25 cm · Medium care · 22–28 °C (72–82 °F)
  • Blackcheek Cichlid and Discus are close in size, but the aggressive one tends to dominate — add discus in a group to spread the pressure.
  • Your 200 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Blackthroat Cichlid⚠️ With caution
  Aggressive · 25 cm · Hard care · 26–30 °C (79–86 °F)
  • Expect Blackthroat Cichlid to harass Discus at times; give dense cover and watch them at feeding.
  • Your 200 L tank is below the ~400 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Blood Parrot Cichlid⚠️ With caution
  Semi-aggressive · 20 cm · Medium care · 24–28 °C (75–82 °F)
  • Blood Parrot Cichlid and Discus are close in size, but the semi-aggressive one tends to dominate — add discus in a group to spread the pressure.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Electric Blue Hap⚠️ With caution
  Semi-aggressive · 20 cm · Medium care · 24–28 °C (75–82 °F)
  • pH preferences only just meet (Discus 5.5–7 vs Electric Blue Hap 7.8–8.5) — target the overlap and acclimate slowly.
  • One likes softer water and the other harder (1–8 vs 10–20 dGH) — a compromise, not a perfect match.
  • Expect Electric Blue Hap to harass Discus at times; give dense cover and watch them at feeding.
  • Your 200 L tank is below the ~250 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Emperor Peacock Cichlid⚠️ With caution
  Semi-aggressive · 16 cm · Medium care · 24–28 °C (75–82 °F)
  • pH preferences only just meet (Discus 5.5–7 vs Emperor Peacock Cichlid 7.6–8.6) — target the overlap and acclimate slowly.
  • One likes softer water and the other harder (1–8 vs 10–20 dGH) — a compromise, not a perfect match.
  • Your 200 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Fire Blue Empress Cichlid⚠️ With caution
  Semi-aggressive · 18 cm · Medium care · 24–28 °C (75–82 °F)
  • pH preferences only just meet (Discus 5.5–7 vs Fire Blue Empress Cichlid 7.5–8.5) — target the overlap and acclimate slowly.
  • One likes softer water and the other harder (1–8 vs 10–20 dGH) — a compromise, not a perfect match.
  • Your 200 L tank is below the ~400 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Goldie Pleco⚠️ With caution
  Semi-aggressive · 20 cm · Medium care · 24–29 °C (75–84 °F)
  • Goldie Pleco and Discus are close in size, but the semi-aggressive one tends to dominate — add discus in a group to spread the pressure.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Green Severum⚠️ With caution
  Semi-aggressive · 20 cm · Medium care · 23–29 °C (73–84 °F)
  • Green Severum and Discus are close in size, but the semi-aggressive one tends to dominate — add discus in a group to spread the pressure.
  • Your 200 L tank is below the ~208 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Honeycomb Pleco⚠️ With caution
  Semi-aggressive · 21 cm · Medium care · 24–29 °C (75–84 °F)
  • Expect Honeycomb Pleco to harass Discus at times; give dense cover and watch them at feeding.
  • Your 200 L tank is below the ~280 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Jack Dempsey⚠️ With caution
  Aggressive · 25 cm · Medium care · 24–28 °C (75–82 °F)
  • Jack Dempsey is aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Platinum Acara⚠️ With caution
  Semi-aggressive · 20 cm · Medium care · 23–28 °C (73–82 °F)
  • Expect Platinum Acara to harass Discus at times; give dense cover and watch them at feeding.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Severum⚠️ With caution
  Semi-aggressive · 25 cm · Medium care · 23–30 °C (73–86 °F)
  • Severum is semi-aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~280 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Spanner Barb⚠️ With caution
  Semi-aggressive · 18 cm · Medium care · 23–29 °C (73–84 °F)
  • Spanner Barb is a notorious fin-nipper — even though Discus is larger, an active shoal will harass its trailing fins. Only safe in a full group of 6+ with plenty of cover.
  • Your 200 L tank is below the ~208 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
  • Keep Spanner Barb in a shoal of 6+ or it gets stressed and nippy.
• Spotted Severum⚠️ With caution
  Semi-aggressive · 25 cm · Medium care · 26–30 °C (79–86 °F)
  • Spotted Severum is semi-aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~300 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Striped Raphael Catfish⚠️ With caution
  Semi-aggressive · 20 cm · Medium care · 24–28 °C (75–82 °F)
  • Striped Raphael Catfish and Discus are close in size, but the semi-aggressive one tends to dominate — add discus in a group to spread the pressure.
  • Keep Discus 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)
  • Discus is bite-sized to a 250 cm predatory alligator gar — it will be eaten.
  • Alligator Gar is aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Clown Knifefish⛔ Not recommended
  Aggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
  • Size gap is too large (90 vs 20 cm): Clown Knifefish will treat Discus as food.
  • Clown Knifefish is aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Fire Eel⛔ Not recommended
  Semi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
  • Discus is bite-sized to a 100 cm predatory fire eel — it will be eaten.
  • Fire Eel clearly outsizes Discus and is semi-aggressive; risky unless the tank is big and well-planted.
  • Your 200 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Koi⛔ Not recommended
  Peaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
  • Koi (90 cm) is big enough to swallow the 20 cm Discus whole.
  • Water hardness preferences differ (Discus 1–8 vs Koi 9–18 dGH).
  • Your 200 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Redtail Catfish⛔ Not recommended
  Aggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
  • Temperature needs don't overlap (Discus 28–31 °C vs Redtail Catfish 24–27 °C).
  • Size gap is too large (120 vs 20 cm): Redtail Catfish will treat Discus as food.
  • Redtail Catfish clearly outsizes Discus and is aggressive; risky unless the tank is big and well-planted.
  • Your 200 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Spotted Gar⛔ Not recommended
  Aggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
  • Temperature needs don't overlap (Discus 28–31 °C vs Spotted Gar 18–26 °C).
  • Discus is bite-sized to a 90 cm predatory spotted gar — it will be eaten.
  • Spotted Gar is aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Wels Catfish⛔ Not recommended
  Aggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
  • Temperature needs don't overlap (Discus 28–31 °C vs Wels Catfish 15–25 °C).
  • Size gap is too large (300 vs 20 cm): Wels Catfish will treat Discus as food.
  • Wels Catfish is aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
  • Your 200 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.
• Wolf Cichlid⛔ Not recommended
  Aggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
  • Size gap is too large (72 vs 20 cm): Wolf Cichlid will treat Discus as food.
  • Expect Wolf Cichlid to harass Discus at times; give dense cover and watch them at feeding.
  • Your 200 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
  • Keep Discus in a shoal of 6+ or it gets stressed and nippy.

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.