Can Neolamprologus Similis and Red Phantom Tetra Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Neolamprologus Similis and Red Phantom Tetra 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

Neolamprologus Similis

Neolamprologus similis

Red Phantom Tetra

Hyphessobrycon sweglesi

🐠Family Group
Neolamprologus Similis
Cichlids - African
Red Phantom Tetra
Characins
Temperament
Neolamprologus Similis
Semi-Aggressive (6/10)
Red Phantom Tetra
Peaceful (1/10)
Temperature
✓ Compatible
Neolamprologus Similis
24–27°C
Red Phantom Tetra
20–24°C
pH Range
✗ No overlap
Neolamprologus Similis
7.8–9
Red Phantom Tetra
4.5–7.5
Hardness (dGH)
✓ Compatible
Neolamprologus Similis
10–25
Red Phantom Tetra
1–10
Water Type
✓ Compatible
Neolamprologus Similis
Freshwater Only
Red Phantom Tetra
Freshwater Only
Flow Preference
✓ Compatible
Neolamprologus Similis
Moderate
Red Phantom Tetra
Low
Min Tank Volume
Combined: 60 L
Neolamprologus Similis
38 L
Red Phantom Tetra
60 L
Swimming Level
✓ Different zones
Neolamprologus Similis
Bottom
Red Phantom Tetra
Middle
🏷️Behavior Tags
Neolamprologus Similis
Nano / Bite-sized (Predation Risk)Territorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Red Phantom Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Neolamprologus Similis and Red Phantom Tetra?

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
Red Phantom Tetra
Test both in my tank

Behaviour & Temperament

Neolamprologus Similis is a moderately assertive species (6/10), while Red Phantom Tetra is peaceful (1/10). This notable difference means Neolamprologus Similis may occasionally assert dominance over Red Phantom Tetra.

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

Water Parameters

The safe temperature window for both species falls between 24°C and 24°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

The pH requirements of Neolamprologus Similis (7.8–9) and Red Phantom Tetra (4.5–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

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

Tank Setup

To house Neolamprologus Similis and Red Phantom Tetra together, plan for an aquarium of at least 60 litres with a minimum length of 60 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), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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 Red Phantom Tetra 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 Neolamprologus Similis and Red Phantom Tetra.

Show 19 more tank sizes

Frequently Asked Questions

Can Neolamprologus Similis and Red Phantom Tetra 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 Red Phantom Tetra need?

A minimum of 60 litres (tank length at least 60 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 Red Phantom Tetra together?

Keep the aquarium between 24°C and 24°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Neolamprologus Similis or Red Phantom Tetra aggressive?

Neolamprologus Similis is moderately assertive (6/10) and Red Phantom Tetra is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Neolamprologus Similis and Red Phantom Tetra need?

Their pH requirements do not overlap. Neolamprologus Similis prefers 7.8–9, while Red Phantom Tetra needs 4.5–7.5. 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 11, 2026
Last updated
May 11, 2026
Issues or corrections?
Contact the editorial team

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