Can Altolamprologus Calvus and Reticulated Hillstream Loach Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 2, 2026
Not Recommended

Altolamprologus Calvus and Reticulated Hillstream Loach 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

Reticulated Hillstream Loach

Sewellia lineolata

🐠Family Group
Altolamprologus Calvus
Cichlids - African
Reticulated Hillstream Loach
Loaches
Temperament
Altolamprologus Calvus
Semi-Aggressive (5/10)
Reticulated Hillstream Loach
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Altolamprologus Calvus
24–28°C
Reticulated Hillstream Loach
20–24°C
pH Range
✗ No overlap
Altolamprologus Calvus
7.8–9
Reticulated Hillstream Loach
6.5–7.5
Hardness (dGH)
✓ Compatible
Altolamprologus Calvus
10–25
Reticulated Hillstream Loach
4–15
Water Type
✓ Compatible
Altolamprologus Calvus
Freshwater Only
Reticulated Hillstream Loach
Freshwater Only
Flow Preference
✓ Compatible
Altolamprologus Calvus
Moderate
Reticulated Hillstream Loach
High
Min Tank Volume
Combined: 114 L
Altolamprologus Calvus
114 L
Reticulated Hillstream Loach
80 L
Swimming Level
Shared: 1 zone
Altolamprologus Calvus
MiddleBottom
Reticulated Hillstream Loach
Bottom
🏷️Behavior Tags
Altolamprologus Calvus
Piscivore (Eats small/nano fish)Fry PredatorShrimp EaterTerritorial (Defends specific area)Shy / Slow Moving (Easily Stressed)
Reticulated Hillstream Loach
Hyperactive / Fast SwimmerTerritorial (Defends specific area)
Stocking calculator

Can your tank handle Altolamprologus Calvus and Reticulated Hillstream Loach?

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
Reticulated Hillstream Loach
Test both in my tank

Behaviour & Temperament

Altolamprologus Calvus is a moderately assertive species (5/10), while Reticulated Hillstream Loach is generally mild-mannered (3/10). This modest difference means Altolamprologus Calvus may occasionally assert dominance over Reticulated Hillstream Loach.

Altolamprologus Calvus and Reticulated Hillstream Loach 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Two territorial species may clash over territory, especially in smaller tanks.

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 Altolamprologus Calvus (7.8–9) and Reticulated Hillstream Loach (6.5–7.5) 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 Reticulated Hillstream Loach together, plan for an aquarium of at least 114 litres with a minimum length of 90 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), Established Algae (Otocinclus), Plants - lighly covered. 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 Reticulated Hillstream Loach 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 Reticulated Hillstream Loach.

Show 10 more tank sizes

Frequently Asked Questions

Can Altolamprologus Calvus and Reticulated Hillstream Loach 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 Reticulated Hillstream Loach need?

A minimum of 114 litres (tank length at least 90 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 Reticulated Hillstream Loach 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 Altolamprologus Calvus or Reticulated Hillstream Loach aggressive?

Altolamprologus Calvus is moderately assertive (5/10) and Reticulated Hillstream Loach is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Altolamprologus Calvus and Reticulated Hillstream Loach need?

Their pH requirements do not overlap. Altolamprologus Calvus prefers 7.8–9, while Reticulated Hillstream Loach needs 6.5–7.5. 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.

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
Issues or corrections?
Contact the editorial team

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