Can Neolamprologus Similis and Peacock Bass Monoculus Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Neolamprologus Similis and Peacock Bass Monoculus are not recommended as tank mates due to conflicting pH requirements and piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Neolamprologus Similis

Neolamprologus similis

Peacock Bass Monoculus

Cichla monoculus

🐠Family Group
Neolamprologus Similis
Cichlids - African
Peacock Bass Monoculus
Cichlids - South American
Temperament
Neolamprologus Similis
Semi-Aggressive (6/10)
Peacock Bass Monoculus
Aggressive (8/10)
Temperature
✓ Compatible
Neolamprologus Similis
24–27°C
Peacock Bass Monoculus
24–29°C
pH Range
✗ No overlap
Neolamprologus Similis
7.8–9
Peacock Bass Monoculus
5.5–7.5
Hardness (dGH)
✓ Compatible
Neolamprologus Similis
10–25
Peacock Bass Monoculus
2–15
Water Type
✓ Compatible
Neolamprologus Similis
Freshwater Only
Peacock Bass Monoculus
Freshwater Only
Flow Preference
✓ Compatible
Neolamprologus Similis
Moderate
Peacock Bass Monoculus
Moderate
Min Tank Volume
Combined: 1000 L
Neolamprologus Similis
38 L
Peacock Bass Monoculus
1000 L
Swimming Level
✓ Different zones
Neolamprologus Similis
Bottom
Peacock Bass Monoculus
TopMiddle
🏷️Behavior Tags
Neolamprologus Similis
Nano / Bite-sized (Predation Risk)Territorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Peacock Bass Monoculus
Piscivore (Eats small/nano fish)Hyperactive / Fast SwimmerJumper (Lid Required)Generally AggressiveTerritorial (Defends specific area)
Stocking calculator

Can your tank handle Neolamprologus Similis and Peacock Bass Monoculus?

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.

Neolamprologus Similis
Peacock Bass Monoculus
Test both in my tank

Behaviour & Temperament

Neolamprologus Similis is a moderately assertive species (6/10), while Peacock Bass Monoculus is semi-aggressive (8/10). This modest difference means Peacock Bass Monoculus may occasionally assert dominance over Neolamprologus Similis.

In terms of spatial distribution, Neolamprologus Similis prefers the Bottom (Substrate) zone, whereas Peacock Bass Monoculus occupies the Top (Surface) and Middle (Open Water) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: Peacock Bass Monoculus 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 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Neolamprologus Similis (7.8–9) and Peacock Bass Monoculus (5.5–7.5) 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 Neolamprologus Similis and Peacock Bass Monoculus together, plan for an aquarium of at least 1000 litres with a minimum length of 240 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), Shells (Breeding/Hiding), 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

Neolamprologus Similis and Peacock Bass Monoculus 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 Neolamprologus Similis and Peacock Bass Monoculus live together?

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

What size tank do Neolamprologus Similis and Peacock Bass Monoculus need?

A minimum of 1000 litres (tank length at least 240 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 Neolamprologus Similis and Peacock Bass Monoculus 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 Neolamprologus Similis or Peacock Bass Monoculus aggressive?

Neolamprologus Similis is moderately assertive (6/10) and Peacock Bass Monoculus is semi-aggressive (8/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Neolamprologus Similis and Peacock Bass Monoculus need?

Their pH requirements do not overlap. Neolamprologus Similis prefers 7.8–9, while Peacock Bass Monoculus needs 5.5–7.5. This makes them incompatible in the same water chemistry.

How do I manage Neolamprologus Similis's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Neolamprologus Similis 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 7, 2026
Last updated
May 7, 2026
Issues or corrections?
Contact the editorial team

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