Can African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

African Knifefish

Xenomystus nigri

Tanganyikan Clown Cichlid (Eretmodus)

Eretmodus cyanostictus

🐠Family Group
African Knifefish
Oddballs
Tanganyikan Clown Cichlid (Eretmodus)
Cichlids - African
Temperament
African Knifefish
Semi-Aggressive (5/10)
Tanganyikan Clown Cichlid (Eretmodus)
Aggressive (7/10)
Temperature
✓ Compatible
African Knifefish
23–28°C
Tanganyikan Clown Cichlid (Eretmodus)
24–28°C
pH Range
✗ No overlap
African Knifefish
6–7.5
Tanganyikan Clown Cichlid (Eretmodus)
8–9.5
Hardness (dGH)
✓ Compatible
African Knifefish
2–15
Tanganyikan Clown Cichlid (Eretmodus)
10–25
Water Type
✓ Compatible
African Knifefish
Freshwater Only
Tanganyikan Clown Cichlid (Eretmodus)
Freshwater Only
Flow Preference
✗ No overlap
African Knifefish
Low
Tanganyikan Clown Cichlid (Eretmodus)
High
Min Tank Volume
Combined: 200 L
African Knifefish
200 L
Tanganyikan Clown Cichlid (Eretmodus)
100 L
Swimming Level
Shared: 1 zone
African Knifefish
MiddleBottom
Tanganyikan Clown Cichlid (Eretmodus)
Bottom
🏷️Behavior Tags
African Knifefish
Piscivore (Eats small/nano fish)Shrimp EaterNocturnalShy / Slow Moving (Easily Stressed)Aggressive to same species/look-alikes
Tanganyikan Clown Cichlid (Eretmodus)
Territorial (Defends specific area)Aggressive to same species/look-alikes
Stocking calculator

Can your tank handle African Knifefish and Tanganyikan Clown Cichlid (Eretmodus)?

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.

African Knifefish
Tanganyikan Clown Cichlid (Eretmodus)
Test both in my tank

Behaviour & Temperament

African Knifefish is a moderately assertive species (5/10), while Tanganyikan Clown Cichlid (Eretmodus) is semi-aggressive (7/10). This modest difference means Tanganyikan Clown Cichlid (Eretmodus) may occasionally assert dominance over African Knifefish.

African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) 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.

Worth noting: African Knifefish 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of African Knifefish (6–7.5) and Tanganyikan Clown Cichlid (Eretmodus) (8–9.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) together, plan for an aquarium of at least 200 litres with a minimum length of 120 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: Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Plants - Floating, Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

African Knifefish prefers Low (Still Water) flow while Tanganyikan Clown Cichlid (Eretmodus) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Why This Pairing Usually Fails in Practice

African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both African Knifefish and Tanganyikan Clown Cichlid (Eretmodus).

Show 5 more tank sizes

Frequently Asked Questions

Can African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) need?

A minimum of 200 litres (tank length at least 120 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 African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are African Knifefish or Tanganyikan Clown Cichlid (Eretmodus) aggressive?

African Knifefish is moderately assertive (5/10) and Tanganyikan Clown Cichlid (Eretmodus) is semi-aggressive (7/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do African Knifefish and Tanganyikan Clown Cichlid (Eretmodus) need?

Their pH requirements do not overlap. African Knifefish prefers 6–7.5, while Tanganyikan Clown Cichlid (Eretmodus) needs 8–9.5. This makes them incompatible in the same water chemistry.

How do I manage Tanganyikan Clown Cichlid (Eretmodus)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Tanganyikan Clown Cichlid (Eretmodus) 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 African Knifefish being nocturnal affect compatibility?

African Knifefish 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 African Knifefish 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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