Can Amazon Leaf Fish and Swordtail Live Together?

🔴Not Recommended

Amazon Leaf Fish and Swordtail 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

Swordtail

Xiphophorus hellerii

🐠Family Group
Amazon Leaf Fish
Other
Swordtail
Livebearers
Temperament
Amazon Leaf Fish
Peaceful (2/10)
Swordtail
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Amazon Leaf Fish
23–29°C
Swordtail
21–28°C
pH Range
✗ No overlap
Amazon Leaf Fish
5–6.8
Swordtail
7–8.3
Hardness (dGH)
✗ No overlap
Amazon Leaf Fish
0–8
Swordtail
12–30
Water Type
✓ Compatible
Amazon Leaf Fish
Freshwater Only
Swordtail
Brackish Tolerant
Flow Preference
✓ Compatible
Amazon Leaf Fish
Low
Swordtail
Moderate
Min Tank Volume
Combined: 132 L
Amazon Leaf Fish
75 L
Swordtail
110 L
Swimming Level
Shared: 2 zones
Amazon Leaf Fish
MiddleTop
Swordtail
TopMiddle
🏷️Behavior Tags
Amazon Leaf Fish
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Nocturnal
Swordtail
Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator

Behaviour & Temperament

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

Amazon Leaf Fish and Swordtail 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. Also, Swordtail is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Amazon Leaf Fish (5–6.8) and Swordtail (7–8.3) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Amazon Leaf Fish needs 0–8 dGH while Swordtail requires 12–30 dGH.

Tank Setup

To house Amazon Leaf Fish and Swordtail 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.

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. 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.

Frequently Asked Questions

Can Amazon Leaf Fish and Swordtail 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 Swordtail 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 Swordtail together?

Keep the aquarium between 23°C and 28°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Amazon Leaf Fish or Swordtail aggressive?

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

What pH do Amazon Leaf Fish and Swordtail need?

Their pH requirements do not overlap. Amazon Leaf Fish prefers 5–6.8, while Swordtail needs 7–8.3. This makes them incompatible in the same water chemistry.

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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