Can Arapaima and Maison Reef Peacock Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Arapaima and Maison Reef Peacock 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

Arapaima

Arapaima gigas

Maison Reef Peacock

Aulonocara stuartgranti "Maison Reef"

🐠Family Group
Arapaima
Oddballs
Maison Reef Peacock
Cichlids - African
Temperament
Arapaima
Aggressive (7/10)
Maison Reef Peacock
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Arapaima
24–30°C
Maison Reef Peacock
24–28°C
pH Range
✗ No overlap
Arapaima
6–7.5
Maison Reef Peacock
7.8–8.6
Hardness (dGH)
✓ Compatible
Arapaima
2–15
Maison Reef Peacock
10–25
Water Type
✓ Compatible
Arapaima
Freshwater Only
Maison Reef Peacock
Freshwater Only
Flow Preference
✓ Compatible
Arapaima
Low
Maison Reef Peacock
Moderate
Min Tank Volume
Combined: 15000 L
Arapaima
15000 L
Maison Reef Peacock
208 L
Swimming Level
Shared: 1 zone
Arapaima
TopMiddle
Maison Reef Peacock
MiddleBottom
🏷️Behavior Tags
Arapaima
Piscivore (Eats small/nano fish)Jumper (Lid Required)Hyperactive / Fast SwimmerPlant DestroyerAggressive to same species/look-alikes
Maison Reef Peacock
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Arapaima and Maison Reef Peacock?

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.

Arapaima
Maison Reef Peacock
Test both in my tank

Behaviour & Temperament

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

Arapaima and Maison Reef Peacock 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: Arapaima 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 Arapaima (6–7.5) and Maison Reef Peacock (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 Arapaima and Maison Reef Peacock together, plan for an aquarium of at least 15000 litres with a minimum length of 600 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). 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.

Why This Pairing Usually Fails in Practice

Arapaima and Maison Reef Peacock 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.

Frequently Asked Questions

Can Arapaima and Maison Reef Peacock live together?

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

What size tank do Arapaima and Maison Reef Peacock need?

A minimum of 15000 litres (tank length at least 600 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 Arapaima and Maison Reef Peacock 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 Arapaima or Maison Reef Peacock aggressive?

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

What pH do Arapaima and Maison Reef Peacock need?

Their pH requirements do not overlap. Arapaima prefers 6–7.5, while Maison Reef Peacock needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Maison Reef Peacock's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Maison Reef Peacock 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 6, 2026
Last updated
May 6, 2026
Issues or corrections?
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