Can Blind Cave Tetra and Florida Flagfish Live Together?

🟢Ideal Tank Mates

Yes, Blind Cave Tetra and Florida Flagfish 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 132 litres is recommended.


At a Glance

Blind Cave Tetra

Astyanax mexicanus

Florida Flagfish

Jordanella floridae

🐠Family Group
Blind Cave Tetra
Characins
Florida Flagfish
Killifish
Temperament
Blind Cave Tetra
Mostly Peaceful (4/10)
Florida Flagfish
Semi-Aggressive (5/10)
Temperature
✓ Compatible
Blind Cave Tetra
20–25°C
Florida Flagfish
18–26°C
pH Range
✓ Compatible
Blind Cave Tetra
6.5–8
Florida Flagfish
6.5–8.5
Hardness (dGH)
✓ Compatible
Blind Cave Tetra
8–20
Florida Flagfish
10–25
Water Type
✓ Compatible
Blind Cave Tetra
Freshwater Only
Florida Flagfish
Brackish Tolerant
Flow Preference
✓ Compatible
Blind Cave Tetra
Moderate
Florida Flagfish
Low
Min Tank Volume
Combined: 132 L
Blind Cave Tetra
110 L
Florida Flagfish
75 L
Swimming Level
Shared: 2 zones
Blind Cave Tetra
MiddleBottom
Florida Flagfish
MiddleBottom
🏷️Behavior Tags
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)
Florida Flagfish
Fin NipperAggressive to same species/look-alikesHyperactive / Fast SwimmerTerritorial (Defends specific area)

Behaviour & Temperament

Blind Cave Tetra is a generally mild-mannered species (4/10), while Florida Flagfish is moderately assertive (5/10). This modest difference means Florida Flagfish may occasionally assert dominance over Blind Cave Tetra.

Blind Cave Tetra and Florida Flagfish 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.

Water Parameters

The safe temperature window for both species falls between 20°C and 25°C. Aim for the midpoint of this range (around 22.5°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–20 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Blind Cave Tetra and Florida Flagfish together, plan for an aquarium of at least 132 litres with a minimum length of 80 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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: Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus), Plants - Densely 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.

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Frequently Asked Questions

Can Blind Cave Tetra and Florida Flagfish live together?

Yes. Blind Cave Tetra and Florida Flagfish are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Blind Cave Tetra and Florida Flagfish need?

A minimum of 132 litres (tank length at least 80 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 Blind Cave Tetra and Florida Flagfish together?

Keep the aquarium between 20°C and 25°C. A target of around 22.5°C sits comfortably within both species' preferred ranges.

Are Blind Cave Tetra or Florida Flagfish aggressive?

Blind Cave Tetra is generally mild-mannered (4/10) and Florida Flagfish is moderately assertive (5/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Blind Cave Tetra and Florida Flagfish need?

Both species overlap in the 6.5–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Blind Cave Tetra nip Florida Flagfish's fins?

Blind Cave Tetra is a known fin nipper. If Florida Flagfish has long or flowing fins, there is a real risk of fin damage. Keeping Blind Cave Tetra in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Florida Flagfish's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Florida Flagfish 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.


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