Can Penguin Tetra and Yellow Peacock Cichlid Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Penguin Tetra 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

Penguin Tetra

Thayeria boehlkei

Yellow Peacock Cichlid

Aulonocara baenschi

🐠Family Group
Penguin Tetra
Characins
Yellow Peacock Cichlid
Cichlids - African
Temperament
Penguin Tetra
Peaceful (2/10)
Yellow Peacock Cichlid
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Penguin Tetra
22–28°C
Yellow Peacock Cichlid
24–28°C
pH Range
✗ No overlap
Penguin Tetra
5.5–7.5
Yellow Peacock Cichlid
7.8–8.6
Hardness (dGH)
✓ Compatible
Penguin Tetra
2–15
Yellow Peacock Cichlid
10–25
Water Type
✓ Compatible
Penguin Tetra
Freshwater Only
Yellow Peacock Cichlid
Freshwater Only
Flow Preference
✓ Compatible
Penguin Tetra
Moderate
Yellow Peacock Cichlid
Moderate
Min Tank Volume
Combined: 200 L
Penguin Tetra
75 L
Yellow Peacock Cichlid
200 L
Swimming Level
Shared: 1 zone
Penguin Tetra
TopMiddle
Yellow Peacock Cichlid
BottomMiddle
🏷️Behavior Tags
Penguin Tetra
Hyperactive / Fast SwimmerJumper (Lid Required)Fin Nipper
Yellow Peacock Cichlid
Digger (Disturbs Substrate)Territorial (Defends specific area)Aggressive to same species/look-alikes
Stocking calculator

Can your tank handle Penguin Tetra 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.

Penguin Tetra
Yellow Peacock Cichlid
Test both in my tank

Behaviour & Temperament

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

Penguin Tetra and Yellow Peacock Cichlid both frequent the Middle (Open Water) 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: Penguin Tetra 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Penguin Tetra (5.5–7.5) 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 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Penguin Tetra and Yellow Peacock Cichlid 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: Plants - Densely covered, Plants - Floating, Sand (Sifters). 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

Penguin Tetra 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 Penguin Tetra and Yellow Peacock Cichlid.

Show 5 more tank sizes

Frequently Asked Questions

Can Penguin Tetra 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 Penguin Tetra and Yellow Peacock Cichlid 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 Penguin Tetra 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 Penguin Tetra or Yellow Peacock Cichlid aggressive?

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

What pH do Penguin Tetra and Yellow Peacock Cichlid need?

Their pH requirements do not overlap. Penguin Tetra prefers 5.5–7.5, while Yellow Peacock Cichlid needs 7.8–8.6. This makes them incompatible in the same water chemistry.

Will Penguin Tetra nip Yellow Peacock Cichlid's fins?

Penguin Tetra is a known fin nipper. If Yellow Peacock Cichlid has long or flowing fins, there is a real risk of fin damage. Keeping Penguin Tetra in a larger group can help redirect nipping behaviour toward conspecifics.

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

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

Related Comparisons