Can Domino Synodontis and Wels Catfish (European Catfish) Live Together?

Possible with Caution

Keeping Domino Synodontis and Wels Catfish (European Catfish) together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 10000 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Domino Synodontis

Synodontis notatus

Wels Catfish (European Catfish)

Silurus glanis

🐟Family Group
Domino Synodontis
Catfish
Wels Catfish (European Catfish)
Catfish
Temperament
Domino Synodontis
Semi-Aggressive (6/10)
Wels Catfish (European Catfish)
Aggressive (8/10)
Temperature
βœ“ Compatible
Domino Synodontis
22–26Β°C
Wels Catfish (European Catfish)
4–25Β°C
pH Range
βœ“ Compatible
Domino Synodontis
6–7.5
Wels Catfish (European Catfish)
6–8
Hardness (dGH)
βœ“ Compatible
Domino Synodontis
4–18
Wels Catfish (European Catfish)
5–20
Water Type
βœ“ Compatible
Domino Synodontis
Freshwater Only
Wels Catfish (European Catfish)
Freshwater Only
Flow Preference
βœ“ Compatible
Domino Synodontis
Moderate
Wels Catfish (European Catfish)
Moderate
Min Tank Volume
Combined: 10000 L
Domino Synodontis
250 L
Wels Catfish (European Catfish)
10000 L
Swimming Level
Shared: 1 zone
Domino Synodontis
MiddleBottom
Wels Catfish (European Catfish)
Bottom
🏷️Behavior Tags
Domino Synodontis
Piscivore (Eats small/nano fish)Aggressive to same species/look-alikesTerritorial (Defends specific area)Hyperactive / Fast Swimmer
Wels Catfish (European Catfish)
Piscivore (Eats small/nano fish)NocturnalGenerally AggressiveTerritorial (Defends specific area)
Stocking calculator

Can your tank handle Domino Synodontis and Wels Catfish (European Catfish)?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Domino Synodontis
Wels Catfish (European Catfish)
Test both in my tank

Behaviour & Temperament

Domino Synodontis is a moderately assertive species (6/10), while Wels Catfish (European Catfish) is semi-aggressive (8/10). This modest difference means Wels Catfish (European Catfish) may occasionally assert dominance over Domino Synodontis.

Domino Synodontis and Wels Catfish (European Catfish) both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: Wels Catfish (European Catfish) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Domino Synodontis and Wels Catfish (European Catfish) to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

Water Parameters

The safe temperature window for both species falls between 22Β°C and 25Β°C. Aim for the midpoint of this range (around 23.5Β°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–18 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Domino Synodontis and Wels Catfish (European Catfish) together, plan for an aquarium of at least 10000 litres with a minimum length of 400 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots β€” caves, driftwood, and dense plant clusters β€” so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

Frequently Asked Questions

Can Domino Synodontis and Wels Catfish (European Catfish) live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 10000 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Domino Synodontis and Wels Catfish (European Catfish) need?

A minimum of 10000 litres (tank length at least 400 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Domino Synodontis and Wels Catfish (European Catfish) together?

Keep the aquarium between 22Β°C and 25Β°C. A target of around 23.5Β°C sits comfortably within both species' preferred ranges.

Are Domino Synodontis or Wels Catfish (European Catfish) aggressive?

Domino Synodontis is moderately assertive (6/10) and Wels Catfish (European Catfish) is semi-aggressive (8/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Domino Synodontis and Wels Catfish (European Catfish) need?

Both species overlap in the 6–7.5 pH range. Consistency is key β€” avoid sudden swings, and test regularly to stay within this window.

How do I manage Domino Synodontis's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Domino Synodontis space to claim a territory without encroaching on the other fish's area. Adding dΓ©cor that divides the tank into distinct zones works especially well.

Does Wels Catfish (European Catfish) being nocturnal affect compatibility?

Wels Catfish (European Catfish) is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Wels Catfish (European Catfish) during evening hours.


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