Can African Knifefish and Clown Killifish Live Together?

Not Recommended

African Knifefish and Clown Killifish are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. 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

Clown Killifish

Epiplatys annulatus

🐠Family Group
African Knifefish
Oddballs
Clown Killifish
Killifish
Temperament
African Knifefish
Semi-Aggressive (5/10)
Clown Killifish
Peaceful (2/10)
Temperature
✓ Compatible
African Knifefish
23–28°C
Clown Killifish
23–27°C
pH Range
✓ Compatible
African Knifefish
6–7.5
Clown Killifish
5–7
Hardness (dGH)
✓ Compatible
African Knifefish
2–15
Clown Killifish
1–8
Water Type
✓ Compatible
African Knifefish
Freshwater Only
Clown Killifish
Freshwater Only
Flow Preference
✓ Compatible
African Knifefish
Low
Clown Killifish
Low
Min Tank Volume
Combined: 200 L
African Knifefish
200 L
Clown Killifish
19 L
Swimming Level
✓ Different zones
African Knifefish
MiddleBottom
Clown Killifish
Top
🏷️Behavior Tags
African Knifefish
Piscivore (Eats small/nano fish)Shrimp EaterNocturnalShy / Slow Moving (Easily Stressed)Aggressive to same species/look-alikes
Clown Killifish
Nano / Bite-sized (Predation Risk)Jumper (Lid Required)Shy / Slow Moving (Easily Stressed)Fry Predator
Stocking calculator

Can your tank handle African Knifefish and Clown Killifish?

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
Clown Killifish
Test both in my tank

Behaviour & Temperament

African Knifefish is a moderately assertive species (5/10), while Clown Killifish is peaceful (2/10). This modest difference means African Knifefish may occasionally assert dominance over Clown Killifish.

In terms of spatial distribution, African Knifefish prefers the Middle (Open Water) and Bottom (Substrate) zones, whereas Clown Killifish occupies the Top (Surface) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: African Knifefish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Clown Killifish is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 23°C and 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–8 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house African Knifefish and Clown Killifish 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, Plants - Densely covered, Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.

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

Suitable Tank Sizes

Standard aquarium sizes large enough for both African Knifefish and Clown Killifish.

Show 5 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. African Knifefish is a known shrimp eater and may prey on small invertebrates or nano fish like Clown Killifish.

Frequently Asked Questions

Can African Knifefish and Clown Killifish 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 Clown Killifish 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 Clown Killifish together?

Keep the aquarium between 23°C and 27°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are African Knifefish or Clown Killifish aggressive?

African Knifefish is moderately assertive (5/10) and Clown Killifish is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do African Knifefish and Clown Killifish need?

Both species overlap in the 6–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

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.


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