Can Arulius Barb and Blind Cave Tetra Live Together?

Ideal Tank Mates

Yes, Arulius Barb and Blind Cave Tetra 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

Arulius Barb

Dawkinsia arulius

Blind Cave Tetra

Astyanax mexicanus

🐠Family Group
Arulius Barb
Cyprinids
Blind Cave Tetra
Characins
Temperament
Arulius Barb
Mostly Peaceful (4/10)
Blind Cave Tetra
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Arulius Barb
19–25°C
Blind Cave Tetra
20–25°C
pH Range
✓ Compatible
Arulius Barb
6–7.5
Blind Cave Tetra
6.5–8
Hardness (dGH)
✓ Compatible
Arulius Barb
2–15
Blind Cave Tetra
8–20
Water Type
✓ Compatible
Arulius Barb
Freshwater Only
Blind Cave Tetra
Freshwater Only
Flow Preference
✓ Compatible
Arulius Barb
High
Blind Cave Tetra
Moderate
Min Tank Volume
Combined: 200 L
Arulius Barb
200 L
Blind Cave Tetra
110 L
Swimming Level
Shared: 2 zones
Arulius Barb
MiddleBottom
Blind Cave Tetra
MiddleBottom
🏷️Behavior Tags
Arulius Barb
Hyperactive / Fast SwimmerJumper (Lid Required)Fin NipperAggressive Eater (Starves shy fish)
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Arulius Barb and Blind Cave Tetra?

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.

Arulius Barb
Blind Cave Tetra
Test both in my tank

Behaviour & Temperament

Both Arulius Barb and Blind Cave Tetra are generally mild-mannered species with an aggression score of 4/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Arulius Barb and Blind Cave Tetra 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: Arulius Barb is a known jumper, so a tight-fitting lid is essential.

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 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 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Arulius Barb and Blind Cave Tetra 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: Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Both species do well with high (river/stream) water movement, so a standard filtration setup rated for the tank volume should suffice.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Arulius Barb and Blind Cave Tetra.

Show 5 more tank sizes

Frequently Asked Questions

Can Arulius Barb and Blind Cave Tetra live together?

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

What size tank do Arulius Barb and Blind Cave Tetra 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 Arulius Barb and Blind Cave Tetra 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 Arulius Barb or Blind Cave Tetra aggressive?

Arulius Barb is generally mild-mannered (4/10) and Blind Cave Tetra is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Arulius Barb and Blind Cave Tetra need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Arulius Barb nip Blind Cave Tetra's fins?

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


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