Can Green Fire Tetra and Redear Sunfish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Green Fire Tetra and Redear Sunfish are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Green Fire Tetra

Aphyocharax rathbuni

Redear Sunfish

Lepomis microlophus

🐠Family Group
Green Fire Tetra
Characins
Redear Sunfish
Other
Temperament
Green Fire Tetra
Peaceful (2/10)
Redear Sunfish
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Green Fire Tetra
20–26°C
Redear Sunfish
10–26°C
pH Range
✓ Compatible
Green Fire Tetra
6.5–7.5
Redear Sunfish
6.5–8.5
Hardness (dGH)
✓ Compatible
Green Fire Tetra
2–15
Redear Sunfish
8–20
Water Type
✓ Compatible
Green Fire Tetra
Freshwater Only
Redear Sunfish
Freshwater Only
Flow Preference
✓ Compatible
Green Fire Tetra
Moderate
Redear Sunfish
Low
Min Tank Volume
Combined: 280 L
Green Fire Tetra
55 L
Redear Sunfish
280 L
Swimming Level
Shared: 1 zone
Green Fire Tetra
MiddleTop
Redear Sunfish
MiddleBottom
🏷️Behavior Tags
Green Fire Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Redear Sunfish
Snail EaterShrimp EaterPiscivore (Eats small/nano fish)Territorial (Defends specific area)Digger (Disturbs Substrate)
Stocking calculator

Can your tank handle Green Fire Tetra and Redear Sunfish?

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.

Green Fire Tetra
Redear Sunfish
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Behaviour & Temperament

Green Fire Tetra is a peaceful species (2/10), while Redear Sunfish is moderately assertive (6/10). This notable difference means Redear Sunfish may occasionally assert dominance over Green Fire Tetra.

Green Fire Tetra and Redear Sunfish 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.

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Water Parameters

The safe temperature window for both species falls between 20°C and 26°C. Aim for the midpoint of this range (around 23.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Green Fire Tetra and Redear Sunfish together, plan for an aquarium of at least 280 litres with a minimum length of 120 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: Plants - Densely covered, Sand (Sifters), Shells (Breeding/Hiding). Meeting these requirements will help both species thrive.

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

Green Fire Tetra and Redear Sunfish 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 Green Fire Tetra and Redear Sunfish.

Show 1 more tank size

Diet & Feeding

Feeding time deserves special attention with this pairing. Redear Sunfish is a known shrimp eater and may prey on small invertebrates or nano fish like Green Fire Tetra.

Frequently Asked Questions

Can Green Fire Tetra and Redear Sunfish live together?

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

What size tank do Green Fire Tetra and Redear Sunfish need?

A minimum of 280 litres (tank length at least 120 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 Green Fire Tetra and Redear Sunfish together?

Keep the aquarium between 20°C and 26°C. A target of around 23.0°C sits comfortably within both species' preferred ranges.

Are Green Fire Tetra or Redear Sunfish aggressive?

Green Fire Tetra is peaceful (2/10) and Redear Sunfish 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 Green Fire Tetra and Redear Sunfish need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Redear Sunfish's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Redear Sunfish space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

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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