Can Peter's Elephantnose Fish and Pseudotropheus Acei Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Peter's Elephantnose Fish and Pseudotropheus Acei 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

Peter's Elephantnose Fish

Gnathonemus petersii

Pseudotropheus Acei

Pseudotropheus acei

🐠Family Group
Peter's Elephantnose Fish
Oddballs
Pseudotropheus Acei
Cichlids - African
Temperament
Peter's Elephantnose Fish
Mostly Peaceful (4/10)
Pseudotropheus Acei
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Peter's Elephantnose Fish
23–28°C
Pseudotropheus Acei
24–28°C
pH Range
✗ No overlap
Peter's Elephantnose Fish
6–7.5
Pseudotropheus Acei
7.8–8.6
Hardness (dGH)
✓ Compatible
Peter's Elephantnose Fish
2–15
Pseudotropheus Acei
10–25
Water Type
✓ Compatible
Peter's Elephantnose Fish
Freshwater Only
Pseudotropheus Acei
Freshwater Only
Flow Preference
✓ Compatible
Peter's Elephantnose Fish
Moderate
Pseudotropheus Acei
Moderate
Min Tank Volume
Combined: 200 L
Peter's Elephantnose Fish
200 L
Pseudotropheus Acei
200 L
Swimming Level
Shared: 2 zones
Peter's Elephantnose Fish
BottomMiddle
Pseudotropheus Acei
TopMiddleBottom
🏷️Behavior Tags
Peter's Elephantnose Fish
NocturnalShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Aggressive to same species/look-alikes
Pseudotropheus Acei
Hyperactive / Fast SwimmerTerritorial (Defends specific area)Fry PredatorPlant Destroyer
Stocking calculator

Can your tank handle Peter's Elephantnose Fish and Pseudotropheus Acei?

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.

Peter's Elephantnose Fish
Pseudotropheus Acei
Test both in my tank

Behaviour & Temperament

Both Peter's Elephantnose Fish and Pseudotropheus Acei are generally mild-mannered species with an aggression score of 4/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Peter's Elephantnose Fish and Pseudotropheus Acei both frequent the Bottom (Substrate) and 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Peter's Elephantnose Fish (6–7.5) and Pseudotropheus Acei (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 Peter's Elephantnose Fish and Pseudotropheus Acei 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), Smooth Gravel (Sensitive Barbels), Plants - lighly covered, Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Pseudotropheus Acei is a plant destroyer, which conflicts with Peter's Elephantnose Fish's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Peter's Elephantnose Fish and Pseudotropheus Acei 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 Peter's Elephantnose Fish and Pseudotropheus Acei.

Show 5 more tank sizes

Frequently Asked Questions

Can Peter's Elephantnose Fish and Pseudotropheus Acei live together?

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

What size tank do Peter's Elephantnose Fish and Pseudotropheus Acei 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 Peter's Elephantnose Fish and Pseudotropheus Acei 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 Peter's Elephantnose Fish or Pseudotropheus Acei aggressive?

Peter's Elephantnose Fish is generally mild-mannered (4/10) and Pseudotropheus Acei is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Peter's Elephantnose Fish and Pseudotropheus Acei need?

Their pH requirements do not overlap. Peter's Elephantnose Fish prefers 6–7.5, while Pseudotropheus Acei needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Pseudotropheus Acei's territorial behaviour?

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

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