Can Rainbow Shark and Red Peacock (Ruby Red) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Rainbow Shark and Red Peacock (Ruby Red) 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

Rainbow Shark

Epalzeorhynchos frenatum

Red Peacock (Ruby Red)

Aulonocara sp. 'Rubescens'

🐠Family Group
Rainbow Shark
Cyprinids
Red Peacock (Ruby Red)
Cichlids - African
Temperament
Rainbow Shark
Aggressive (7/10)
Red Peacock (Ruby Red)
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Rainbow Shark
22–28°C
Red Peacock (Ruby Red)
24–28°C
pH Range
✗ No overlap
Rainbow Shark
6.5–7.5
Red Peacock (Ruby Red)
7.8–8.6
Hardness (dGH)
✓ Compatible
Rainbow Shark
5–15
Red Peacock (Ruby Red)
10–25
Water Type
✓ Compatible
Rainbow Shark
Freshwater Only
Red Peacock (Ruby Red)
Freshwater Only
Flow Preference
✓ Compatible
Rainbow Shark
Moderate
Red Peacock (Ruby Red)
Moderate
Min Tank Volume
Combined: 208 L
Rainbow Shark
200 L
Red Peacock (Ruby Red)
208 L
Swimming Level
Shared: 1 zone
Rainbow Shark
Bottom
Red Peacock (Ruby Red)
MiddleBottom
🏷️Behavior Tags
Rainbow Shark
Territorial (Defends specific area)Aggressive to same species/look-alikesHyperactive / Fast SwimmerJumper (Lid Required)
Red Peacock (Ruby Red)
Digger (Disturbs Substrate)Fry PredatorTerritorial (Defends specific area)Aggressive to same species/look-alikesHyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Rainbow Shark and Red Peacock (Ruby Red)?

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.

Rainbow Shark
Red Peacock (Ruby Red)
Test both in my tank

Behaviour & Temperament

Rainbow Shark is a semi-aggressive species (7/10), while Red Peacock (Ruby Red) is moderately assertive (6/10). This modest difference means Rainbow Shark may occasionally assert dominance over Red Peacock (Ruby Red).

Rainbow Shark and Red Peacock (Ruby Red) both frequent the 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.

Worth noting: Rainbow Shark 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 Rainbow Shark (6.5–7.5) and Red Peacock (Ruby Red) (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 Rainbow Shark and Red Peacock (Ruby Red) 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), Driftwood (Digestion/Hiding), Plants - Densely covered. 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

Rainbow Shark and Red Peacock (Ruby Red) 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 Rainbow Shark and Red Peacock (Ruby Red).

Show 5 more tank sizes

Frequently Asked Questions

Can Rainbow Shark and Red Peacock (Ruby Red) live together?

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

What size tank do Rainbow Shark and Red Peacock (Ruby Red) 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 Rainbow Shark and Red Peacock (Ruby Red) 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 Rainbow Shark or Red Peacock (Ruby Red) aggressive?

Rainbow Shark is semi-aggressive (7/10) and Red Peacock (Ruby Red) is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Rainbow Shark and Red Peacock (Ruby Red) need?

Their pH requirements do not overlap. Rainbow Shark prefers 6.5–7.5, while Red Peacock (Ruby Red) needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Rainbow Shark's territorial behaviour?

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