Can Butterfly Peacock Cichlid and Clown Killifish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 3, 2026
Not Recommended

Butterfly Peacock Cichlid and Clown Killifish are not recommended as tank mates due to conflicting pH requirements and incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Butterfly Peacock Cichlid

Aulonocara jacobfreibergi

Clown Killifish

Epiplatys annulatus

🐠Family Group
Butterfly Peacock Cichlid
Cichlids - African
Clown Killifish
Killifish
Temperament
Butterfly Peacock Cichlid
Semi-Aggressive (6/10)
Clown Killifish
Peaceful (2/10)
Temperature
✓ Compatible
Butterfly Peacock Cichlid
24–28°C
Clown Killifish
23–27°C
pH Range
✗ No overlap
Butterfly Peacock Cichlid
7.8–8.6
Clown Killifish
5–7
Hardness (dGH)
✗ No overlap
Butterfly Peacock Cichlid
10–25
Clown Killifish
1–8
Water Type
✓ Compatible
Butterfly Peacock Cichlid
Freshwater Only
Clown Killifish
Freshwater Only
Flow Preference
✓ Compatible
Butterfly Peacock Cichlid
Moderate
Clown Killifish
Low
Min Tank Volume
Combined: 208 L
Butterfly Peacock Cichlid
208 L
Clown Killifish
19 L
Swimming Level
✓ Different zones
Butterfly Peacock Cichlid
MiddleBottom
Clown Killifish
Top
🏷️Behavior Tags
Butterfly Peacock Cichlid
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Fry PredatorHyperactive / Fast Swimmer
Clown Killifish
Nano / Bite-sized (Predation Risk)Jumper (Lid Required)Shy / Slow Moving (Easily Stressed)Fry Predator
Stocking calculator

Can your tank handle Butterfly Peacock Cichlid 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.

Butterfly Peacock Cichlid
Clown Killifish
Test both in my tank

Behaviour & Temperament

Butterfly Peacock Cichlid is a moderately assertive species (6/10), while Clown Killifish is peaceful (2/10). This notable difference means Butterfly Peacock Cichlid may occasionally assert dominance over Clown Killifish.

In terms of spatial distribution, Butterfly Peacock Cichlid 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Clown Killifish is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Butterfly Peacock Cichlid (7.8–8.6) and Clown Killifish (5–7) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Butterfly Peacock Cichlid needs 10–25 dGH while Clown Killifish requires 1–8 dGH.

Tank Setup

To house Butterfly Peacock Cichlid and Clown Killifish together, plan for an aquarium of at least 208 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: Sand (Sifters), 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 moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Usually Fails in Practice

Butterfly Peacock Cichlid and Clown Killifish 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 Butterfly Peacock Cichlid and Clown Killifish.

Show 5 more tank sizes

Frequently Asked Questions

Can Butterfly Peacock Cichlid 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 Butterfly Peacock Cichlid and Clown Killifish need?

A minimum of 208 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 Butterfly Peacock Cichlid and Clown Killifish together?

Keep the aquarium between 24°C and 27°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Butterfly Peacock Cichlid or Clown Killifish aggressive?

Butterfly Peacock Cichlid is moderately assertive (6/10) and Clown Killifish is peaceful (2/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Butterfly Peacock Cichlid and Clown Killifish need?

Their pH requirements do not overlap. Butterfly Peacock Cichlid prefers 7.8–8.6, while Clown Killifish needs 5–7. This makes them incompatible in the same water chemistry.

How do I manage Butterfly Peacock Cichlid's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Butterfly Peacock Cichlid 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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 3, 2026
Last updated
May 3, 2026
Issues or corrections?
Contact the editorial team

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