Can Amazon Leaf Fish and Blind Cave Tetra Live Together?

🟡Possible with Caution

Keeping Amazon Leaf Fish and Blind Cave Tetra together is possible but requires caution due to 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

Amazon Leaf Fish

Monocirrhus polyacanthus

Blind Cave Tetra

Astyanax mexicanus

🐠Family Group
Amazon Leaf Fish
Other
Blind Cave Tetra
Characins
Temperament
Amazon Leaf Fish
Peaceful (2/10)
Blind Cave Tetra
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Amazon Leaf Fish
23–29°C
Blind Cave Tetra
20–25°C
pH Range
✓ Compatible
Amazon Leaf Fish
5–6.8
Blind Cave Tetra
6.5–8
Hardness (dGH)
✓ Compatible
Amazon Leaf Fish
0–8
Blind Cave Tetra
8–20
Water Type
✓ Compatible
Amazon Leaf Fish
Freshwater Only
Blind Cave Tetra
Freshwater Only
Flow Preference
✓ Compatible
Amazon Leaf Fish
Low
Blind Cave Tetra
Moderate
Min Tank Volume
Combined: 132 L
Amazon Leaf Fish
75 L
Blind Cave Tetra
110 L
Swimming Level
Shared: 1 zone
Amazon Leaf Fish
MiddleTop
Blind Cave Tetra
MiddleBottom
🏷️Behavior Tags
Amazon Leaf Fish
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Nocturnal
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)

Behaviour & Temperament

Amazon Leaf Fish is a peaceful species (2/10), while Blind Cave Tetra is generally mild-mannered (4/10). This modest difference means Blind Cave Tetra may occasionally assert dominance over Amazon Leaf Fish.

Amazon Leaf Fish and Blind Cave Tetra 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.

Worth noting: Amazon Leaf Fish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

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 23°C and 25°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 6.8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–8 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Amazon Leaf Fish and Blind Cave Tetra 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: Leaf Litter/Blackwater, Plants - Densely covered, Driftwood (Digestion/Hiding), Plants - Floating, Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Both species do well with low (still water) 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 Amazon Leaf Fish 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 Amazon Leaf Fish receives an adequate share.

Frequently Asked Questions

Can Amazon Leaf Fish and Blind Cave Tetra 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 Amazon Leaf Fish and Blind Cave Tetra 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 Amazon Leaf Fish and Blind Cave Tetra together?

Keep the aquarium between 23°C and 25°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Amazon Leaf Fish or Blind Cave Tetra aggressive?

Amazon Leaf Fish is peaceful (2/10) and Blind Cave Tetra is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Amazon Leaf Fish and Blind Cave Tetra need?

Both species overlap in the 6.5–6.8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Blind Cave Tetra nip Amazon Leaf Fish's fins?

Blind Cave Tetra is a known fin nipper. If Amazon Leaf Fish 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.

Does Amazon Leaf Fish being nocturnal affect compatibility?

Amazon Leaf Fish is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Amazon Leaf Fish during evening hours.


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