Can Finger Fish and Redline Rasbora Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Finger Fish and Redline Rasbora are not recommended as tank mates due to incompatible water types and conflicting pH requirements and incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Finger Fish

Monodactylus argenteus

Redline Rasbora

Rasbora pauciperforata

🐠Family Group
Finger Fish
Oddballs
Redline Rasbora
Cyprinids
Temperament
Finger Fish
Semi-Aggressive (5/10)
Redline Rasbora
Peaceful (1/10)
Temperature
✓ Compatible
Finger Fish
24–28°C
Redline Rasbora
22–27°C
pH Range
✗ No overlap
Finger Fish
7.5–8.5
Redline Rasbora
4–6.8
Hardness (dGH)
✗ No overlap
Finger Fish
12–30
Redline Rasbora
1–8
Water Type
✗ No overlap
Finger Fish
Brackish Required
Redline Rasbora
Freshwater Only
Flow Preference
✓ Compatible
Finger Fish
Moderate
Redline Rasbora
Low
Min Tank Volume
Combined: 470 L
Finger Fish
470 L
Redline Rasbora
80 L
Swimming Level
Shared: 1 zone
Finger Fish
Middle
Redline Rasbora
TopMiddle
🏷️Behavior Tags
Finger Fish
Hyperactive / Fast SwimmerFin NipperPlant DestroyerAggressive to same species/look-alikes
Redline Rasbora
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Jumper (Lid Required)
Stocking calculator

Can your tank handle Finger Fish and Redline 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.

Finger Fish
Redline Rasbora
Test both in my tank

Behaviour & Temperament

Finger Fish is a moderately assertive species (5/10), while Redline Rasbora is peaceful (1/10). This notable difference means Finger Fish may occasionally assert dominance over Redline Rasbora.

Finger Fish and Redline 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.

Worth noting: Redline Rasbora is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Finger Fish (7.5–8.5) and Redline Rasbora (4–6.8) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Finger Fish needs 12–30 dGH while Redline Rasbora requires 1–8 dGH.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Finger Fish and Redline Rasbora together, plan for an aquarium of at least 470 litres with a minimum length of 150 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), Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Densely covered, Plants - Floating. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Finger Fish is a plant destroyer, which conflicts with Redline Rasbora's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Why This Pairing Usually Fails in Practice

Finger Fish and Redline Rasbora are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Finger Fish and Redline Rasbora.

Frequently Asked Questions

Can Finger Fish and Redline Rasbora live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Finger Fish and Redline Rasbora need?

A minimum of 470 litres (tank length at least 150 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 Finger Fish and Redline Rasbora together?

Keep the aquarium between 24°C and 27°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Finger Fish or Redline Rasbora aggressive?

Finger Fish is moderately assertive (5/10) and Redline Rasbora is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Finger Fish and Redline Rasbora need?

Their pH requirements do not overlap. Finger Fish prefers 7.5–8.5, while Redline Rasbora needs 4–6.8. This makes them incompatible in the same water chemistry.

Will Finger Fish nip Redline Rasbora's fins?

Finger Fish is a known fin nipper. If Redline Rasbora has long or flowing fins, there is a real risk of fin damage. Keeping Finger Fish in a larger group can help redirect nipping behaviour toward conspecifics.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
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