Can Finger Fish and Wels Catfish (European Catfish) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Finger Fish and Wels Catfish (European Catfish) are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Finger Fish

Monodactylus argenteus

Wels Catfish (European Catfish)

Silurus glanis

🐠Family Group
Finger Fish
Oddballs
Wels Catfish (European Catfish)
Catfish
Temperament
Finger Fish
Semi-Aggressive (5/10)
Wels Catfish (European Catfish)
Aggressive (8/10)
Temperature
✓ Compatible
Finger Fish
24–28°C
Wels Catfish (European Catfish)
4–25°C
pH Range
✓ Compatible
Finger Fish
7.5–8.5
Wels Catfish (European Catfish)
6–8
Hardness (dGH)
✓ Compatible
Finger Fish
12–30
Wels Catfish (European Catfish)
5–20
Water Type
✗ No overlap
Finger Fish
Brackish Required
Wels Catfish (European Catfish)
Freshwater Only
Flow Preference
✓ Compatible
Finger Fish
Moderate
Wels Catfish (European Catfish)
Moderate
Min Tank Volume
Combined: 10000 L
Finger Fish
470 L
Wels Catfish (European Catfish)
10000 L
Swimming Level
✓ Different zones
Finger Fish
Middle
Wels Catfish (European Catfish)
Bottom
🏷️Behavior Tags
Finger Fish
Hyperactive / Fast SwimmerFin NipperPlant DestroyerAggressive to same species/look-alikes
Wels Catfish (European Catfish)
Piscivore (Eats small/nano fish)NocturnalGenerally AggressiveTerritorial (Defends specific area)
Stocking calculator

Can your tank handle Finger Fish 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.

Finger Fish
Wels Catfish (European Catfish)
Test both in my tank

Behaviour & Temperament

Finger Fish is a moderately assertive species (5/10), while Wels Catfish (European Catfish) is semi-aggressive (8/10). This modest difference means Wels Catfish (European Catfish) may occasionally assert dominance over Finger Fish.

In terms of spatial distribution, Finger Fish prefers the Middle (Open Water) zone, whereas Wels Catfish (European Catfish) occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

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

Water Parameters

The safe temperature window for both species falls between 24°C and 25°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–20 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Finger Fish 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.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

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.

Why This Pairing Usually Fails in Practice

Finger Fish and Wels Catfish (European Catfish) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Frequently Asked Questions

Can Finger Fish and Wels Catfish (European Catfish) live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Finger Fish 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 Finger Fish and Wels Catfish (European Catfish) together?

Keep the aquarium between 24°C and 25°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Finger Fish or Wels Catfish (European Catfish) aggressive?

Finger Fish is moderately assertive (5/10) and Wels Catfish (European Catfish) is semi-aggressive (8/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Finger Fish and Wels Catfish (European Catfish) need?

Both species overlap in the 7.5–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Finger Fish nip Wels Catfish (European Catfish)'s fins?

Finger Fish is a known fin nipper. If Wels Catfish (European Catfish) has long or flowing fins, there is a real risk of fin damage. Keeping Finger Fish in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Wels Catfish (European Catfish)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Wels Catfish (European Catfish) space to claim a territory without encroaching on the other fish's area. Adding décor 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.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

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