Can Neolamprologus Similis and Peter's Elephantnose Fish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Neolamprologus Similis and Peter's Elephantnose Fish 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

Peter's Elephantnose Fish

Gnathonemus petersii

🐠Family Group
Neolamprologus Similis
Cichlids - African
Peter's Elephantnose Fish
Oddballs
Temperament
Neolamprologus Similis
Semi-Aggressive (6/10)
Peter's Elephantnose Fish
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Neolamprologus Similis
24–27°C
Peter's Elephantnose Fish
23–28°C
pH Range
✗ No overlap
Neolamprologus Similis
7.8–9
Peter's Elephantnose Fish
6–7.5
Hardness (dGH)
✓ Compatible
Neolamprologus Similis
10–25
Peter's Elephantnose Fish
2–15
Water Type
✓ Compatible
Neolamprologus Similis
Freshwater Only
Peter's Elephantnose Fish
Freshwater Only
Flow Preference
✓ Compatible
Neolamprologus Similis
Moderate
Peter's Elephantnose Fish
Moderate
Min Tank Volume
Combined: 200 L
Neolamprologus Similis
38 L
Peter's Elephantnose Fish
200 L
Swimming Level
Shared: 1 zone
Neolamprologus Similis
Bottom
Peter's Elephantnose Fish
BottomMiddle
🏷️Behavior Tags
Neolamprologus Similis
Nano / Bite-sized (Predation Risk)Territorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Peter's Elephantnose Fish
NocturnalShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Aggressive to same species/look-alikes
Stocking calculator

Can your tank handle Neolamprologus Similis and Peter's Elephantnose Fish?

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
Peter's Elephantnose Fish
Test both in my tank

Behaviour & Temperament

Neolamprologus Similis is a moderately assertive species (6/10), while Peter's Elephantnose Fish is generally mild-mannered (4/10). This modest difference means Neolamprologus Similis may occasionally assert dominance over Peter's Elephantnose Fish.

Neolamprologus Similis and Peter's Elephantnose Fish 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.

Worth noting: Peter's Elephantnose Fish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Peter's Elephantnose Fish 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 Peter's Elephantnose Fish (6–7.5) 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 Peter's Elephantnose Fish 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: Sand (Sifters), Shells (Breeding/Hiding), Smooth Gravel (Sensitive Barbels), Plants - lighly covered, 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 Peter's Elephantnose Fish 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 Peter's Elephantnose Fish.

Show 5 more tank sizes

Frequently Asked Questions

Can Neolamprologus Similis and Peter's Elephantnose Fish 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 Peter's Elephantnose Fish 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 Neolamprologus Similis and Peter's Elephantnose Fish 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 Peter's Elephantnose Fish aggressive?

Neolamprologus Similis is moderately assertive (6/10) and Peter's Elephantnose Fish is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Neolamprologus Similis and Peter's Elephantnose Fish need?

Their pH requirements do not overlap. Neolamprologus Similis prefers 7.8–9, while Peter's Elephantnose Fish needs 6–7.5. 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.

Does Peter's Elephantnose Fish being nocturnal affect compatibility?

Peter's Elephantnose Fish is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Peter's Elephantnose Fish during evening hours.

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?
Contact the editorial team

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