Can Oscar and Peacock Cichlid (Aulonocara) Live Together?

🔴Not Recommended

Oscar and Peacock Cichlid (Aulonocara) 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

Oscar

Astronotus ocellatus

Peacock Cichlid (Aulonocara)

Aulonocara sp.

🐠Family Group
Oscar
Cichlids - South American
Peacock Cichlid (Aulonocara)
Cichlids - African
Temperament
Oscar
Aggressive (7/10)
Peacock Cichlid (Aulonocara)
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Oscar
23–27°C
Peacock Cichlid (Aulonocara)
24–28°C
pH Range
✗ No overlap
Oscar
6–7.5
Peacock Cichlid (Aulonocara)
7.8–8.6
Hardness (dGH)
✓ Compatible
Oscar
5–15
Peacock Cichlid (Aulonocara)
10–25
Water Type
✓ Compatible
Oscar
Freshwater Only
Peacock Cichlid (Aulonocara)
Freshwater Only
Flow Preference
✓ Compatible
Oscar
Moderate
Peacock Cichlid (Aulonocara)
Moderate
Min Tank Volume
Combined: 336 L
Oscar
280 L
Peacock Cichlid (Aulonocara)
200 L
Swimming Level
Shared: 2 zones
Oscar
MiddleBottom
Peacock Cichlid (Aulonocara)
BottomMiddle
🏷️Behavior Tags
Oscar
Piscivore (Eats small/nano fish)Digger (Disturbs Substrate)Plant DestroyerTerritorial (Defends specific area)Generally AggressiveHyperactive / Fast Swimmer
Peacock Cichlid (Aulonocara)
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)

Behaviour & Temperament

Oscar is a semi-aggressive species (7/10), while Peacock Cichlid (Aulonocara) is moderately assertive (6/10). This modest difference means Oscar may occasionally assert dominance over Peacock Cichlid (Aulonocara).

Oscar and Peacock Cichlid (Aulonocara) both frequent the Middle (Open Water) and 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.

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 Oscar (6–7.5) and Peacock Cichlid (Aulonocara) (7.8–8.6) 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. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Oscar and Peacock Cichlid (Aulonocara) together, plan for an aquarium of at least 336 litres with a minimum length of 120 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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), 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.

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Frequently Asked Questions

Can Oscar and Peacock Cichlid (Aulonocara) live together?

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

What size tank do Oscar and Peacock Cichlid (Aulonocara) need?

A minimum of 336 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 Oscar and Peacock Cichlid (Aulonocara) 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 Oscar or Peacock Cichlid (Aulonocara) aggressive?

Oscar is semi-aggressive (7/10) and Peacock Cichlid (Aulonocara) is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Oscar and Peacock Cichlid (Aulonocara) need?

Their pH requirements do not overlap. Oscar prefers 6–7.5, while Peacock Cichlid (Aulonocara) needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Oscar's territorial behaviour?

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


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