Can Keyhole Cichlid and Peter's Elephantnose Fish Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Ideal Tank Mates

Yes, Keyhole Cichlid and Peter's Elephantnose Fish are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. A minimum tank size of 200 litres is recommended.


At a Glance

Keyhole Cichlid

Cleithracara maronii

Peter's Elephantnose Fish

Gnathonemus petersii

🐠Family Group
Keyhole Cichlid
Cichlids - South American
Peter's Elephantnose Fish
Oddballs
Temperament
Keyhole Cichlid
Peaceful (2/10)
Peter's Elephantnose Fish
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Keyhole Cichlid
22–28°C
Peter's Elephantnose Fish
23–28°C
pH Range
✓ Compatible
Keyhole Cichlid
6–7.5
Peter's Elephantnose Fish
6–7.5
Hardness (dGH)
✓ Compatible
Keyhole Cichlid
2–15
Peter's Elephantnose Fish
2–15
Water Type
✓ Compatible
Keyhole Cichlid
Freshwater Only
Peter's Elephantnose Fish
Freshwater Only
Flow Preference
✓ Compatible
Keyhole Cichlid
Low
Peter's Elephantnose Fish
Moderate
Min Tank Volume
Combined: 200 L
Keyhole Cichlid
110 L
Peter's Elephantnose Fish
200 L
Swimming Level
Shared: 2 zones
Keyhole Cichlid
MiddleBottom
Peter's Elephantnose Fish
BottomMiddle
🏷️Behavior Tags
Keyhole Cichlid
Shy / Slow Moving (Easily Stressed)Fry Predator
Peter's Elephantnose Fish
NocturnalShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Aggressive to same species/look-alikes
Stocking calculator

Can your tank handle Keyhole Cichlid 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.

Keyhole Cichlid
Peter's Elephantnose Fish
Test both in my tank

Behaviour & Temperament

Keyhole Cichlid is a peaceful species (2/10), while Peter's Elephantnose Fish is generally mild-mannered (4/10). This modest difference means Peter's Elephantnose Fish may occasionally assert dominance over Keyhole Cichlid.

Keyhole Cichlid and Peter's Elephantnose Fish both frequent the Middle (Open Water) and 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 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Keyhole Cichlid 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: Driftwood (Digestion/Hiding), Plants - Densely covered, Leaf Litter/Blackwater, Sand (Sifters), Smooth Gravel (Sensitive Barbels), Plants - lighly covered. Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Works in Practice

Keyhole Cichlid and Peter's Elephantnose Fish work best when the tank gives each fish enough room to use its preferred level of the aquarium and enough cover to avoid constant visual contact. The score matters, but the real-world success usually comes from matching their pace, keeping water stable, and resisting the urge to crowd the tank just because the pair looks safe on paper.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Keyhole Cichlid and Peter's Elephantnose Fish.

Show 5 more tank sizes

Frequently Asked Questions

Can Keyhole Cichlid and Peter's Elephantnose Fish live together?

Yes. Keyhole Cichlid and Peter's Elephantnose Fish are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Keyhole Cichlid 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 Keyhole Cichlid and Peter's Elephantnose Fish together?

Keep the aquarium between 23°C and 28°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Keyhole Cichlid or Peter's Elephantnose Fish aggressive?

Keyhole Cichlid is peaceful (2/10) and Peter's Elephantnose Fish is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Keyhole Cichlid and Peter's Elephantnose Fish need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

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
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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