Can Amazon Leaf Fish and Blackline Rasbora Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 1, 2026
Possible with Caution

Keeping Amazon Leaf Fish and Blackline Rasbora together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 75 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

Blackline Rasbora

Rasbora borapetensis

🐠Family Group
Amazon Leaf Fish
Other
Blackline Rasbora
Cyprinids
Temperament
Amazon Leaf Fish
Peaceful (2/10)
Blackline Rasbora
Peaceful (1/10)
Temperature
✓ Compatible
Amazon Leaf Fish
23–29°C
Blackline Rasbora
22–26°C
pH Range
✓ Compatible
Amazon Leaf Fish
5–6.8
Blackline Rasbora
6–7.5
Hardness (dGH)
✓ Compatible
Amazon Leaf Fish
0–8
Blackline Rasbora
2–15
Water Type
✓ Compatible
Amazon Leaf Fish
Freshwater Only
Blackline Rasbora
Freshwater Only
Flow Preference
✓ Compatible
Amazon Leaf Fish
Low
Blackline Rasbora
Moderate
Min Tank Volume
Combined: 75 L
Amazon Leaf Fish
75 L
Blackline Rasbora
60 L
Swimming Level
Shared: 2 zones
Amazon Leaf Fish
MiddleTop
Blackline Rasbora
MiddleTop
🏷️Behavior Tags
Amazon Leaf Fish
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Nocturnal
Blackline Rasbora
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)
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Can your tank handle Amazon Leaf Fish and Blackline Rasbora?

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.

Amazon Leaf Fish
Blackline Rasbora
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Behaviour & Temperament

Amazon Leaf Fish is a peaceful species (2/10), while Blackline Rasbora is peaceful (1/10). This modest difference means Amazon Leaf Fish may occasionally assert dominance over Blackline Rasbora.

Amazon Leaf Fish and Blackline Rasbora both frequent the Middle (Open Water) and Top (Surface) 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. Also, Blackline Rasbora is a known jumper, so a tight-fitting lid is essential.

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.

Water Parameters

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 2–8 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Amazon Leaf Fish and Blackline Rasbora together, plan for an aquarium of at least 75 litres with a minimum length of 60 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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. 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.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Amazon Leaf Fish and Blackline Rasbora need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Amazon Leaf Fish and Blackline Rasbora.

Show 17 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Blackline Rasbora is an aggressive eater that may prevent Amazon Leaf Fish from getting enough food.

Because Blackline Rasbora 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 Blackline Rasbora live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 75 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Amazon Leaf Fish and Blackline Rasbora need?

A minimum of 75 litres (tank length at least 60 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 Blackline Rasbora together?

Keep the aquarium between 23°C and 26°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Amazon Leaf Fish or Blackline Rasbora aggressive?

Amazon Leaf Fish is peaceful (2/10) and Blackline Rasbora is peaceful (1/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Amazon Leaf Fish and Blackline Rasbora need?

Both species overlap in the 6–6.8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

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.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 1, 2026
Last updated
May 1, 2026
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