Can Altolamprologus Calvus and Fire Eel Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 2, 2026
Not Recommended

Altolamprologus Calvus and Fire Eel 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

Altolamprologus Calvus

Altolamprologus calvus

Fire Eel

Mastacembelus erythrotaenia

🐠Family Group
Altolamprologus Calvus
Cichlids - African
Fire Eel
Oddballs
Temperament
Altolamprologus Calvus
Semi-Aggressive (5/10)
Fire Eel
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Altolamprologus Calvus
24–28°C
Fire Eel
24–28°C
pH Range
✗ No overlap
Altolamprologus Calvus
7.8–9
Fire Eel
6–7.5
Hardness (dGH)
✓ Compatible
Altolamprologus Calvus
10–25
Fire Eel
5–15
Water Type
✓ Compatible
Altolamprologus Calvus
Freshwater Only
Fire Eel
Freshwater Only
Flow Preference
✓ Compatible
Altolamprologus Calvus
Moderate
Fire Eel
Moderate
Min Tank Volume
Combined: 680 L
Altolamprologus Calvus
114 L
Fire Eel
680 L
Swimming Level
Shared: 1 zone
Altolamprologus Calvus
MiddleBottom
Fire Eel
Bottom
🏷️Behavior Tags
Altolamprologus Calvus
Piscivore (Eats small/nano fish)Fry PredatorShrimp EaterTerritorial (Defends specific area)Shy / Slow Moving (Easily Stressed)
Fire Eel
Piscivore (Eats small/nano fish)Shrimp EaterDigger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Altolamprologus Calvus and Fire Eel?

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.

Altolamprologus Calvus
Fire Eel
Test both in my tank

Behaviour & Temperament

Altolamprologus Calvus is a moderately assertive species (5/10), while Fire Eel is generally mild-mannered (4/10). This modest difference means Altolamprologus Calvus may occasionally assert dominance over Fire Eel.

Altolamprologus Calvus and Fire Eel 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: Fire Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Fire Eel 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 Altolamprologus Calvus (7.8–9) and Fire Eel (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 Altolamprologus Calvus and Fire Eel together, plan for an aquarium of at least 680 litres with a minimum length of 180 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), 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

Altolamprologus Calvus and Fire Eel 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 Altolamprologus Calvus and Fire Eel.

Frequently Asked Questions

Can Altolamprologus Calvus and Fire Eel live together?

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

What size tank do Altolamprologus Calvus and Fire Eel need?

A minimum of 680 litres (tank length at least 180 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 Altolamprologus Calvus and Fire Eel 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 Altolamprologus Calvus or Fire Eel aggressive?

Altolamprologus Calvus is moderately assertive (5/10) and Fire Eel is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Altolamprologus Calvus and Fire Eel need?

Their pH requirements do not overlap. Altolamprologus Calvus prefers 7.8–9, while Fire Eel needs 6–7.5. This makes them incompatible in the same water chemistry.

How do I manage Altolamprologus Calvus's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Altolamprologus Calvus 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 Fire Eel being nocturnal affect compatibility?

Fire Eel 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 Fire Eel during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 2, 2026
Last updated
May 2, 2026
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