Wels Catfish Tank Mates

Wels Catfish is aggressive and a demanding tank mate. Here's what can (and mostly can't) share its tank — and why.

By The Aquarium DB Team • Updated June 7, 2026 • Full Wels Catfish care guide →
Best matches

The best tank mates for a wels catfish

Honestly, very few. Wels Catfish is best kept on its own, or only with exceptionally robust, similarly-tempered fish in a large tank. Use the checker above and the "avoid" list below to see why typical community fish don't work.

With caution

Wels Catfish tank mates that can work with care

  • Adolf's Cory ⚠️ With caution
    Medium care · Peaceful · 5.5 cm · 22–26 °C (72–79 °F)
    Wels Catfish 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 caution
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    Wels Catfish 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 caution
    Easy care · Peaceful · 3 cm · 22–26 °C (72–79 °F)
    Wels Catfish 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 caution
    Easy care · Peaceful · 5 cm · 23–28 °C (73–82 °F)
    Wels Catfish 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 caution
    Easy care · Peaceful · 5 cm · 22–27 °C (72–81 °F)
    Wels Catfish may bully the smaller Bandit Corydoras, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Bearded Corydoras ⚠️ With caution
    Medium care · Peaceful · 10 cm · 18–24 °C (64–75 °F)
    Wels Catfish 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 caution
    Hard care · Peaceful · 60 cm · 22–28 °C (72–82 °F)
    Wels Catfish may bully the smaller Black Doras Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Blood Red Tiger Pleco ⚠️ With caution
    Medium care · Peaceful · 6 cm · 24–29 °C (75–84 °F)
    Wels Catfish may bully the smaller Blood Red Tiger Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.

+ 45 more “with caution” pairings — see the interactive checker above.

Avoid

Fish to avoid keeping with a wels catfish

  • Mekong Giant Catfish ⛔ Avoid
    Hard care · Semi-aggressive · 300 cm · 20–28 °C (68–82 °F)
    Wels Catfish and Mekong Giant 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)
    Wels Catfish 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)
    Wels Catfish 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)
    Two assertive fish, one genuinely aggressive: Wels Catfish and Fire Eel will hold territory and clash.
  • Clown Knifefish ⛔ Avoid
    Hard care · Aggressive · 90 cm · 24–28 °C (75–82 °F)
    Two assertive fish, one genuinely aggressive: Wels Catfish and Clown Knifefish will hold territory and clash.
  • Koi ⛔ Avoid
    Medium care · Peaceful · 90 cm · 4–28 °C (39–82 °F)
    Koi is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
  • Spotted Gar ⛔ Avoid
    Hard care · Aggressive · 90 cm · 18–26 °C (64–79 °F)
    Wels Catfish 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: Wels Catfish and Wolf Cichlid will hold territory and clash.

+ 279 more to avoid — the checker above flags every one.

Interactive tool

Check any fish against a wels catfish

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

Tank-mate checker

Will it live with a Wels Catfish?

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

  • Bearded Corydoras⚠️ With caution
    Peaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
    • Wels Catfish may bully the smaller Bearded Corydoras, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
    • Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Black Doras Catfish⚠️ With caution
    Peaceful · 60 cm · Hard care · 22–28 °C (72–82 °F)
    • Wels Catfish may bully the smaller Black Doras Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Bristlenose Pleco⚠️ With caution
    Peaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
    • Wels Catfish may bully the smaller Bristlenose Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Clown Pleco⚠️ With caution
    Peaceful · 9 cm · Medium care · 24–28 °C (75–82 °F)
    • Wels Catfish may bully the smaller Clown Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Common Pleco⚠️ With caution
    Peaceful · 45 cm · Medium care · 22–28 °C (72–82 °F)
    • Wels Catfish may bully the smaller Common Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Giant Glass Catfish⚠️ With caution
    Peaceful · 15 cm · Medium care · 22–27 °C (72–81 °F)
    • Wels Catfish clearly outsizes Giant Glass Catfish and is aggressive; risky unless the tank is big and well-planted.
    • Wels Catfish may bully the smaller Giant Glass Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Leopard Frog Pleco⚠️ With caution
    Peaceful · 9 cm · Medium care · 25–30 °C (77–86 °F)
    • Wels Catfish may bully the smaller Leopard Frog Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Marbled Hoplo⚠️ With caution
    Peaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
    • Wels Catfish may bully the smaller Marbled Hoplo, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Porthole Catfish⚠️ With caution
    Peaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
    • Wels Catfish may bully the smaller Porthole Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Rubber Lip Pleco⚠️ With caution
    Peaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
    • Wels Catfish may bully the smaller Rubber Lip Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Sailfin Pleco⚠️ With caution
    Peaceful · 50 cm · Medium care · 22–28 °C (72–82 °F)
    • Wels Catfish may bully the smaller Sailfin Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Snowball Pleco⚠️ With caution
    Peaceful · 16 cm · Medium care · 24–30 °C (75–86 °F)
    • Wels Catfish may bully the smaller Snowball Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Spotted Rubbernose Pleco⚠️ With caution
    Peaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
    • Wels Catfish may bully the smaller Spotted Rubbernose Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Spotted Talking Catfish⚠️ With caution
    Peaceful · 15 cm · Easy care · 22–26 °C (72–79 °F)
    • Wels Catfish may bully the smaller Spotted Talking Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Upside-down Catfish⚠️ With caution
    Peaceful · 10 cm · Easy care · 22–26 °C (72–79 °F)
    • Wels Catfish may bully the smaller Upside-down Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Yellow-spotted Pleco⚠️ With caution
    Peaceful · 35 cm · Medium care · 24–27 °C (75–81 °F)
    • Wels Catfish may bully the smaller Yellow-spotted Pleco, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Alligator Gar⛔ Not recommended
    Aggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
    • Wels Catfish and Alligator Gar are both territorial and at least one is outright aggressive — expect serious fighting.
  • Clown Knifefish⛔ Not recommended
    Aggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
    • Two assertive fish, one genuinely aggressive: Wels Catfish and Clown Knifefish will hold territory and clash.
    • Clown Knifefish is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
  • Fire Eel⛔ Not recommended
    Semi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
    • Two assertive fish, one genuinely aggressive: Wels Catfish and Fire Eel will hold territory and clash.
    • Wels Catfish (300 cm) is big enough to swallow the 100 cm Fire Eel whole.
  • Koi⛔ Not recommended
    Peaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
    • Koi is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
    • Wels Catfish is aggressive and may chase or nip the smaller Koi — plant heavily and break up sight lines.
  • Mekong Giant Catfish⛔ Not recommended
    Semi-aggressive · 300 cm · Hard care · 20–28 °C (68–82 °F)
    • Wels Catfish and Mekong Giant Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Your 20000 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)
    • Wels Catfish and Redtail Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Wels Catfish may bully the smaller Redtail Catfish, though its armour makes it a hard meal — give it caves and driftwood to retreat into.
  • Spotted Gar⛔ Not recommended
    Aggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
    • Wels Catfish and Spotted Gar are both territorial and at least one is outright aggressive — expect serious fighting.
    • Wels Catfish (300 cm) is big enough to swallow the 90 cm Spotted Gar whole.
  • Wolf Cichlid⛔ Not recommended
    Aggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
    • Two assertive fish, one genuinely aggressive: Wels Catfish and Wolf Cichlid will hold territory and clash.
    • Size gap is too large (300 vs 72 cm): Wels Catfish will treat Wolf Cichlid as food.

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 wels catfish community tank

Give the group a stable, planted 20000 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 wels catfish

Wels Catfish 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 bottom of the tank, so it pairs naturally with species that use the other levels.

Wels Catfish grows to about 300 cm, so avoid tank mates small enough to be seen as food — as a rule of thumb, skip anything under roughly 150 cm. Match its water, too: aim for 15–25 °C (59–77 °F), pH 6.5–7.5 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.

Wels Catfish 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 wels catfish live with other fish?

Barely. Wels Catfish is best kept on its own or only with exceptionally robust, similarly-tempered fish in a large tank — see why below.

What is the best tank mate for a wels catfish?

There isn't a safe community match — wels catfish needs robust, species-appropriate housing rather than typical community tank mates.

What fish should you avoid keeping with a wels catfish?

Avoid Mekong Giant 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 wels catfish tank mates need?

Start from Wels Catfish's own minimum and scale up with every addition. The checker above defaults to a 20000 L community tank and flags pairings that need more room — drag the slider to match your setup.

← Back to the full Wels Catfish care guide