Can Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) 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

Blue Tetra

Knodus borki

Fosso Cichlid (Fossorochromis rostratus)

Fossorochromis rostratus

🐠Family Group
Blue Tetra
Characins
Fosso Cichlid (Fossorochromis rostratus)
Cichlids - African
Temperament
Blue Tetra
Semi-Aggressive (5/10)
Fosso Cichlid (Fossorochromis rostratus)
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Blue Tetra
22–26°C
Fosso Cichlid (Fossorochromis rostratus)
24–28°C
pH Range
✗ No overlap
Blue Tetra
5.5–7.5
Fosso Cichlid (Fossorochromis rostratus)
7.8–8.6
Hardness (dGH)
✓ Compatible
Blue Tetra
2–12
Fosso Cichlid (Fossorochromis rostratus)
10–25
Water Type
✓ Compatible
Blue Tetra
Freshwater Only
Fosso Cichlid (Fossorochromis rostratus)
Freshwater Only
Flow Preference
✓ Compatible
Blue Tetra
Moderate
Fosso Cichlid (Fossorochromis rostratus)
Moderate
Min Tank Volume
Combined: 680 L
Blue Tetra
90 L
Fosso Cichlid (Fossorochromis rostratus)
680 L
Swimming Level
Shared: 1 zone
Blue Tetra
TopMiddle
Fosso Cichlid (Fossorochromis rostratus)
BottomMiddle
🏷️Behavior Tags
Blue Tetra
Hyperactive / Fast SwimmerFin NipperAggressive to same species/look-alikesJumper (Lid Required)
Fosso Cichlid (Fossorochromis rostratus)
Digger (Disturbs Substrate)Territorial (Defends specific area)Hyperactive / Fast SwimmerPiscivore (Eats small/nano fish)
Stocking calculator

Can your tank handle Blue Tetra and Fosso Cichlid (Fossorochromis rostratus)?

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.

Blue Tetra
Fosso Cichlid (Fossorochromis rostratus)
Test both in my tank

Behaviour & Temperament

Blue Tetra is a moderately assertive species (5/10), while Fosso Cichlid (Fossorochromis rostratus) is moderately assertive (6/10). This modest difference means Fosso Cichlid (Fossorochromis rostratus) may occasionally assert dominance over Blue Tetra.

Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) both frequent the 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.

Worth noting: Blue Tetra 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 26°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Blue Tetra (5.5–7.5) and Fosso Cichlid (Fossorochromis rostratus) (7.8–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) 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: Plants - Densely covered, Sand (Sifters). 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

Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) 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 Blue Tetra and Fosso Cichlid (Fossorochromis rostratus).

Frequently Asked Questions

Can Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) live together?

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

What size tank do Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) 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 Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) together?

Keep the aquarium between 24°C and 26°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Blue Tetra or Fosso Cichlid (Fossorochromis rostratus) aggressive?

Blue Tetra is moderately assertive (5/10) and Fosso Cichlid (Fossorochromis rostratus) is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Blue Tetra and Fosso Cichlid (Fossorochromis rostratus) need?

Their pH requirements do not overlap. Blue Tetra prefers 5.5–7.5, while Fosso Cichlid (Fossorochromis rostratus) needs 7.8–8.6. This makes them incompatible in the same water chemistry.

Will Blue Tetra nip Fosso Cichlid (Fossorochromis rostratus)'s fins?

Blue Tetra is a known fin nipper. If Fosso Cichlid (Fossorochromis rostratus) has long or flowing fins, there is a real risk of fin damage. Keeping Blue Tetra in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Fosso Cichlid (Fossorochromis rostratus)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Fosso Cichlid (Fossorochromis rostratus) 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 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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