Can Threadfin Acara and Yellow Peacock Cichlid Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Threadfin Acara and Yellow Peacock Cichlid 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

Threadfin Acara

Acarichthys heckelii

Yellow Peacock Cichlid

Aulonocara baenschi

🐠Family Group
Threadfin Acara
Cichlids - South American
Yellow Peacock Cichlid
Cichlids - African
Temperament
Threadfin Acara
Mostly Peaceful (4/10)
Yellow Peacock Cichlid
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Threadfin Acara
24–28°C
Yellow Peacock Cichlid
24–28°C
pH Range
✗ No overlap
Threadfin Acara
6–7.5
Yellow Peacock Cichlid
7.8–8.6
Hardness (dGH)
✓ Compatible
Threadfin Acara
1–12
Yellow Peacock Cichlid
10–25
Water Type
✓ Compatible
Threadfin Acara
Freshwater Only
Yellow Peacock Cichlid
Freshwater Only
Flow Preference
✓ Compatible
Threadfin Acara
Moderate
Yellow Peacock Cichlid
Moderate
Min Tank Volume
Combined: 250 L
Threadfin Acara
250 L
Yellow Peacock Cichlid
200 L
Swimming Level
Shared: 2 zones
Threadfin Acara
MiddleBottom
Yellow Peacock Cichlid
BottomMiddle
🏷️Behavior Tags
Threadfin Acara
Digger (Disturbs Substrate)Territorial (Defends specific area)Fry Predator
Yellow Peacock Cichlid
Digger (Disturbs Substrate)Territorial (Defends specific area)Aggressive to same species/look-alikes
Stocking calculator

Can your tank handle Threadfin Acara and Yellow Peacock Cichlid?

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.

Threadfin Acara
Yellow Peacock Cichlid
Test both in my tank

Behaviour & Temperament

Threadfin Acara is a generally mild-mannered species (4/10), while Yellow Peacock Cichlid is moderately assertive (6/10). This modest difference means Yellow Peacock Cichlid may occasionally assert dominance over Threadfin Acara.

Threadfin Acara and Yellow Peacock Cichlid 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Threadfin Acara (6–7.5) and Yellow Peacock Cichlid (7.8–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Threadfin Acara and Yellow Peacock Cichlid together, plan for an aquarium of at least 250 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), 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

Threadfin Acara and Yellow Peacock Cichlid 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 Threadfin Acara and Yellow Peacock Cichlid.

Show 1 more tank size

Frequently Asked Questions

Can Threadfin Acara and Yellow Peacock Cichlid live together?

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

What size tank do Threadfin Acara and Yellow Peacock Cichlid need?

A minimum of 250 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 Threadfin Acara and Yellow Peacock Cichlid 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 Threadfin Acara or Yellow Peacock Cichlid aggressive?

Threadfin Acara is generally mild-mannered (4/10) and Yellow Peacock Cichlid is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Threadfin Acara and Yellow Peacock Cichlid need?

Their pH requirements do not overlap. Threadfin Acara prefers 6–7.5, while Yellow Peacock Cichlid needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Threadfin Acara's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Threadfin Acara 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 11, 2026
Last updated
May 11, 2026
Issues or corrections?
Contact the editorial team

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