Jack Dempsey Tank Mates
Jack Dempsey is aggressive, so its tank mates need choosing with care. Here are the 9 freshwater species that pair well with a jack dempsey — plus the 271 to avoid — with a live checker you can tune to your own tank.
The best tank mates for a jack dempsey
- Bristlenose Pleco ✅ CompatibleEasy care · Peaceful · 12 cm · 23–30 °C (73–86 °F)Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Rubber Lip Pleco ✅ CompatibleEasy care · Peaceful · 12 cm · 20–26 °C (68–79 °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.
- Marbled Hoplo ✅ CompatibleEasy care · Peaceful · 14 cm · 22–28 °C (72–82 °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.
- Spotted Talking Catfish ✅ CompatibleEasy care · Peaceful · 15 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.
- Weather Loach ✅ CompatibleEasy care · Peaceful · 25 cm · 5–24 °C (41–75 °F)Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–24 °C — no size, zone or temperament conflicts.
- Medusa Pleco ✅ CompatibleMedium care · Peaceful · 12 cm · 26–30 °C (79–86 °F)Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 26–28 °C — no size, zone or temperament conflicts.
- Spotted Rubbernose Pleco ✅ CompatibleMedium care · Peaceful · 12 cm · 20–26 °C (68–79 °F)Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
- Snowball Pleco ✅ CompatibleMedium care · Peaceful · 16 cm · 24–30 °C (75–86 °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.
- Elephant-nose Knifefish ✅ CompatibleHard care · Peaceful · 35 cm · 24–29 °C (75–84 °F)Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
Jack Dempsey tank mates that can work with care
- Adolf's Cory ⚠️ With cautionMedium care · Peaceful · 5.5 cm · 22–26 °C (72–79 °F)Jack Dempsey may bully the smaller Adolf's Cory, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Agassiz's Corydoras ⚠️ With cautionEasy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)Jack Dempsey may bully the smaller Agassiz's Corydoras, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Assassin Snail ⚠️ With cautionEasy care · Peaceful · 3 cm · 22–26 °C (72–79 °F)Jack Dempsey may bully the smaller Assassin Snail, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Axelrod's Cory ⚠️ With cautionEasy care · Peaceful · 5 cm · 23–28 °C (73–82 °F)Jack Dempsey may bully the smaller Axelrod's Cory, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Bandit Corydoras ⚠️ With cautionEasy care · Peaceful · 5 cm · 22–27 °C (72–81 °F)Jack Dempsey may bully the smaller Bandit Corydoras, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Banjo Catfish ⚠️ With cautionMedium care · Peaceful · 15 cm · 20–26 °C (68–79 °F)Jack Dempsey may hunt Banjo Catfish, fry or shrimplets — safest in a heavily planted tank.
- Bearded Corydoras ⚠️ With cautionMedium care · Peaceful · 10 cm · 18–24 °C (64–75 °F)Jack Dempsey may bully the smaller Bearded Corydoras, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
- Black Doras Catfish ⚠️ With cautionHard care · Peaceful · 60 cm · 22–28 °C (72–82 °F)Jack Dempsey is small enough to tempt Black Doras Catfish; only risk it in a densely planted setup with hiding spots.
+ 52 more “with caution” pairings — see the interactive checker above.
Fish to avoid keeping with a jack dempsey
- Mekong Giant Catfish ⛔ AvoidHard care · Semi-aggressive · 300 cm · 20–28 °C (68–82 °F)Two assertive fish, one genuinely aggressive: Jack Dempsey and Mekong Giant Catfish will hold territory and clash.
- Wels Catfish ⛔ AvoidHard care · Aggressive · 300 cm · 15–25 °C (59–77 °F)Two assertive fish, one genuinely aggressive: Jack Dempsey and Wels Catfish will hold territory and clash.
- Alligator Gar ⛔ AvoidHard care · Aggressive · 250 cm · 24–28 °C (75–82 °F)Two assertive fish, one genuinely aggressive: Jack Dempsey and Alligator Gar will hold territory and clash.
- Redtail Catfish ⛔ AvoidHard care · Aggressive · 120 cm · 24–27 °C (75–81 °F)Two assertive fish, one genuinely aggressive: Jack Dempsey and Redtail Catfish will hold territory and clash.
- Fire Eel ⛔ AvoidMedium care · Semi-aggressive · 100 cm · 24–28 °C (75–82 °F)Jack Dempsey and Fire Eel are both territorial and at least one is outright aggressive — expect serious fighting.
- Clown Knifefish ⛔ AvoidHard care · Aggressive · 90 cm · 24–28 °C (75–82 °F)Jack Dempsey and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
- Koi ⛔ AvoidMedium care · Peaceful · 90 cm · 4–28 °C (39–82 °F)Jack Dempsey is bite-sized to a 90 cm koi — it will be eaten.
- Spotted Gar ⛔ AvoidHard care · Aggressive · 90 cm · 18–26 °C (64–79 °F)Two assertive fish, one genuinely aggressive: Jack Dempsey and Spotted Gar will hold territory and clash.
+ 263 more to avoid — the checker above flags every one.
Check any fish against a jack dempsey
Dial in your exact tank size and filter by result — the checker scores every species in our database against a jack dempsey, with the reasoning for each verdict.
Tank-mate checker
Will it live with a Jack Dempsey?
We compare each fish against your jack dempsey on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Bristlenose Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Elephant-nose Knifefish✅ CompatiblePeaceful · 35 cm · Hard care · 24–29 °C (75–84 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Marbled Hoplo✅ CompatiblePeaceful · 14 cm · Easy care · 22–28 °C (72–82 °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.
- Medusa Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 26–28 °C — no size, zone or temperament conflicts.
- Rubber Lip Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 20–26 °C (68–79 °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.
- Snowball Pleco✅ CompatiblePeaceful · 16 cm · Medium care · 24–30 °C (75–86 °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.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
- Spotted Talking Catfish✅ CompatiblePeaceful · 15 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.
- Weather Loach✅ CompatiblePeaceful · 25 cm · Easy care · 5–24 °C (41–75 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–24 °C — no size, zone or temperament conflicts.
- Banjo Catfish⚠️ With cautionPeaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
- Jack Dempsey may hunt Banjo Catfish, fry or shrimplets — safest in a heavily planted tank.
- Boesemani Rainbowfish⚠️ With cautionPeaceful · 11 cm · Medium care · 24–28 °C (75–82 °F)
- Jack Dempsey is aggressive and may chase or nip the smaller Boesemani Rainbowfish — plant heavily and break up sight lines.
- Boesemani Rainbowfish is small enough to tempt Jack Dempsey; only risk it in a densely planted setup with hiding spots.
- Keep Boesemani Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Clown Loach⚠️ With cautionPeaceful · 30 cm · Medium care · 25–30 °C (77–86 °F)
- Your 210 L tank is below the ~400 L this pairing really wants — crowding raises aggression.
- Common Pleco⚠️ With cautionPeaceful · 45 cm · Medium care · 22–28 °C (72–82 °F)
- Watch for Common Pleco picking off any jack dempsey small enough to fit in its mouth.
- Your 210 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Denison Barb⚠️ With cautionPeaceful · 15 cm · Medium care · 18–25 °C (64–77 °F)
- Jack Dempsey is aggressive and may chase or nip the smaller Denison Barb — plant heavily and break up sight lines.
- Watch for Jack Dempsey picking off any denison barb small enough to fit in its mouth.
- Keep Denison Barb in a shoal of 6+ or it gets stressed and nippy.
- Discus⚠️ With cautionPeaceful · 20 cm · Hard care · 28–31 °C (82–88 °F)
- Jack Dempsey is aggressive and may chase or nip the smaller Discus — plant heavily and break up sight lines.
- Keep Discus in a shoal of 6+ or it gets stressed and nippy.
- Giant Betta⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Jack Dempsey is aggressive and may chase or nip the smaller Giant Betta — plant heavily and break up sight lines.
- Giant Betta is small enough to tempt Jack Dempsey; only risk it in a densely planted setup with hiding spots.
- Giant Glass Catfish⚠️ With cautionPeaceful · 15 cm · Medium care · 22–27 °C (72–81 °F)
- Expect Jack Dempsey to harass Giant Glass Catfish at times; give dense cover and watch them at feeding.
- Giant Kuhli Loach⚠️ With cautionPeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Giant Kuhli Loach is small enough to tempt Jack Dempsey; only risk it in a densely planted setup with hiding spots.
- Mascara Barb⚠️ With cautionPeaceful · 12 cm · Medium care · 20–25 °C (68–77 °F)
- Jack Dempsey is aggressive and may chase or nip the smaller Mascara Barb — plant heavily and break up sight lines.
- Mascara Barb is small enough to tempt Jack Dempsey; only risk it in a densely planted setup with hiding spots.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Moonlight Gourami⚠️ With cautionPeaceful · 15 cm · Easy care · 25–30 °C (77–86 °F)
- Jack Dempsey clearly outsizes Moonlight Gourami and is aggressive; risky unless the tank is big and well-planted.
- Jack Dempsey may hunt Moonlight Gourami, fry or shrimplets — safest in a heavily planted tank.
- Murray River Rainbowfish⚠️ With cautionPeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Expect Jack Dempsey to harass Murray River Rainbowfish at times; give dense cover and watch them at feeding.
- Jack Dempsey may hunt Murray River Rainbowfish, fry or shrimplets — safest in a heavily planted tank.
- Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Pearl Gourami⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Jack Dempsey clearly outsizes Pearl Gourami and is aggressive; risky unless the tank is big and well-planted.
- Pearl Gourami is small enough to tempt Jack Dempsey; only risk it in a densely planted setup with hiding spots.
- Sailfin Pleco⚠️ With cautionPeaceful · 50 cm · Medium care · 22–28 °C (72–82 °F)
- Your 210 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Striped Eel Loach⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Striped Eel Loach is small enough to tempt Jack Dempsey; only risk it in a densely planted setup with hiding spots.
- Yellow-spotted Pleco⚠️ With cautionPeaceful · 35 cm · Medium care · 24–27 °C (75–81 °F)
- Your 210 L tank is below the ~280 L this pairing really wants — crowding raises aggression.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Two assertive fish, one genuinely aggressive: Jack Dempsey and Alligator Gar will hold territory and clash.
- Alligator Gar (250 cm) is big enough to swallow the 25 cm Jack Dempsey whole.
- Your 210 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Jack Dempsey and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (90 vs 25 cm): Clown Knifefish will treat Jack Dempsey as food.
- Your 210 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Jack Dempsey and Fire Eel are both territorial and at least one is outright aggressive — expect serious fighting.
- Fire Eel (100 cm) is big enough to swallow the 25 cm Jack Dempsey whole.
- Your 210 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Jack Dempsey is bite-sized to a 90 cm koi — it will be eaten.
- Your 210 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Mekong Giant Catfish⛔ Not recommendedSemi-aggressive · 300 cm · Hard care · 20–28 °C (68–82 °F)
- Two assertive fish, one genuinely aggressive: Jack Dempsey and Mekong Giant Catfish will hold territory and clash.
- Your 210 L tank is below the ~100000 L this pairing really wants — crowding raises aggression.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Two assertive fish, one genuinely aggressive: Jack Dempsey and Redtail Catfish will hold territory and clash.
- Redtail Catfish (120 cm) is big enough to swallow the 25 cm Jack Dempsey whole.
- Your 210 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Two assertive fish, one genuinely aggressive: Jack Dempsey and Spotted Gar will hold territory and clash.
- Jack Dempsey is bite-sized to a 90 cm predatory spotted gar — it will be eaten.
- Your 210 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Two assertive fish, one genuinely aggressive: Jack Dempsey and Wels Catfish will hold territory and clash.
- Size gap is too large (300 vs 25 cm): Wels Catfish will treat Jack Dempsey as food.
- Your 210 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 jack dempsey community tank
Give the group a stable, planted 210 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 the right tank mates for a jack dempsey
Jack Dempsey 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 middle of the tank, so it pairs naturally with species that use the other levels.
Jack Dempsey grows to about 25 cm, so avoid tank mates small enough to be seen as food — as a rule of thumb, skip anything under roughly 13 cm. Match its water, too: aim for 24–28 °C (75–82 °F), pH 6–8 and 5–15 dGH. Fish needing very different conditions — coldwater species, or hard-water lovers against a soft-water fish — rarely thrive side by side.
Jack Dempsey 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.
Frequently asked questions
Can a jack dempsey live with other fish?
Yes — with the right companions. Our checker finds 9 compatible freshwater species for jack dempsey. 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 jack dempsey?
Easy, peaceful, similarly-sized species top the list — for example Bristlenose Pleco, Rubber Lip Pleco, Marbled Hoplo. Use the checker above to match against your own tank size.
What fish should you avoid keeping with a jack dempsey?
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 jack dempsey tank mates need?
Start from Jack Dempsey's own minimum and scale up with every addition. The checker above defaults to a 210 L community tank and flags pairings that need more room — drag the slider to match your setup.