Can Blind Cave Tetra and Chili Rasbora Live Together?

🟡Possible with Caution

Keeping Blind Cave Tetra and Chili Rasbora together is possible but requires caution due to differing aggression levels and potential behavioral clashes. Provide a spacious tank of at least 132 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Blind Cave Tetra

Astyanax mexicanus

Chili Rasbora

Boraras brigittae

🐠Family Group
Blind Cave Tetra
Characins
Chili Rasbora
Cyprinids
Temperament
Blind Cave Tetra
Mostly Peaceful (4/10)
Chili Rasbora
Peaceful (0/10)
Temperature
✓ Compatible
Blind Cave Tetra
20–25°C
Chili Rasbora
24–28°C
pH Range
✓ Compatible
Blind Cave Tetra
6.5–8
Chili Rasbora
4–7
Hardness (dGH)
✓ Compatible
Blind Cave Tetra
8–20
Chili Rasbora
1–10
Water Type
✓ Compatible
Blind Cave Tetra
Freshwater Only
Chili Rasbora
Freshwater Only
Flow Preference
✓ Compatible
Blind Cave Tetra
Moderate
Chili Rasbora
Low
Min Tank Volume
Combined: 132 L
Blind Cave Tetra
110 L
Chili Rasbora
19 L
Swimming Level
Shared: 1 zone
Blind Cave Tetra
MiddleBottom
Chili Rasbora
MiddleTop
🏷️Behavior Tags
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)
Chili Rasbora
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)

Behaviour & Temperament

Blind Cave Tetra is a generally mild-mannered species (4/10), while Chili Rasbora is peaceful (0/10). This notable difference means Blind Cave Tetra may occasionally assert dominance over Chili Rasbora.

Blind Cave Tetra and Chili Rasbora 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 24°C and 25°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–10 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 Chili Rasbora 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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.

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Diet & Feeding

Feeding time deserves special attention with this pairing. Blind Cave Tetra is an aggressive eater that may prevent Chili Rasbora from getting enough food.

Because Blind Cave Tetra is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Chili Rasbora receives an adequate share.

Frequently Asked Questions

Can Blind Cave Tetra and Chili Rasbora live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 132 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Blind Cave Tetra and Chili Rasbora 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 Chili Rasbora together?

Keep the aquarium between 24°C and 25°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Blind Cave Tetra or Chili Rasbora aggressive?

Blind Cave Tetra is generally mild-mannered (4/10) and Chili Rasbora is peaceful (0/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Blind Cave Tetra and Chili Rasbora need?

Both species overlap in the 6.5–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Blind Cave Tetra nip Chili Rasbora's fins?

Blind Cave Tetra is a known fin nipper. If Chili Rasbora 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.


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