Can Amazon Leaf Fish and Redtail Splitfin Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Amazon Leaf Fish and Redtail Splitfin are not recommended as tank mates due to 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

Amazon Leaf Fish

Monocirrhus polyacanthus

Redtail Splitfin

Xenotoca eiseni

🐠Family Group
Amazon Leaf Fish
Other
Redtail Splitfin
Livebearers
Temperament
Amazon Leaf Fish
Peaceful (2/10)
Redtail Splitfin
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Amazon Leaf Fish
23–29°C
Redtail Splitfin
18–26°C
pH Range
✗ No overlap
Amazon Leaf Fish
5–6.8
Redtail Splitfin
7–8.5
Hardness (dGH)
✗ No overlap
Amazon Leaf Fish
0–8
Redtail Splitfin
10–25
Water Type
✓ Compatible
Amazon Leaf Fish
Freshwater Only
Redtail Splitfin
Freshwater Only
Flow Preference
✓ Compatible
Amazon Leaf Fish
Low
Redtail Splitfin
Moderate
Min Tank Volume
Combined: 110 L
Amazon Leaf Fish
75 L
Redtail Splitfin
110 L
Swimming Level
Shared: 2 zones
Amazon Leaf Fish
MiddleTop
Redtail Splitfin
TopMiddle
🏷️Behavior Tags
Amazon Leaf Fish
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Nocturnal
Redtail Splitfin
Fin NipperFry PredatorHyperactive / Fast SwimmerPlant Destroyer
Stocking calculator

Can your tank handle Amazon Leaf Fish and Redtail Splitfin?

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
Redtail Splitfin
Test both in my tank

Behaviour & Temperament

Amazon Leaf Fish is a peaceful species (2/10), while Redtail Splitfin is moderately assertive (6/10). This notable difference means Redtail Splitfin may occasionally assert dominance over Amazon Leaf Fish.

Amazon Leaf Fish and Redtail Splitfin 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.

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

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.

The pH requirements of Amazon Leaf Fish (5–6.8) and Redtail Splitfin (7–8.5) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Amazon Leaf Fish needs 0–8 dGH while Redtail Splitfin requires 10–25 dGH.

Tank Setup

To house Amazon Leaf Fish and Redtail Splitfin together, plan for an aquarium of at least 110 litres with a minimum length of 80 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: Leaf Litter/Blackwater, Plants - Densely covered, Driftwood (Digestion/Hiding), Plants - Floating, Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

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

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 Usually Fails in Practice

Amazon Leaf Fish and Redtail Splitfin 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 Amazon Leaf Fish and Redtail Splitfin.

Show 12 more tank sizes

Frequently Asked Questions

Can Amazon Leaf Fish and Redtail Splitfin live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Amazon Leaf Fish and Redtail Splitfin need?

A minimum of 110 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 Redtail Splitfin 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 Redtail Splitfin aggressive?

Amazon Leaf Fish is peaceful (2/10) and Redtail Splitfin is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Amazon Leaf Fish and Redtail Splitfin need?

Their pH requirements do not overlap. Amazon Leaf Fish prefers 5–6.8, while Redtail Splitfin needs 7–8.5. This makes them incompatible in the same water chemistry.

Will Redtail Splitfin nip Amazon Leaf Fish's fins?

Redtail Splitfin is a known fin nipper. If Amazon Leaf Fish has long or flowing fins, there is a real risk of fin damage. Keeping Redtail Splitfin 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.

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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