Can Green Fire Tetra and Uaru Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Green Fire Tetra and Uaru are not recommended as tank mates due to no temperature overlap. 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

Uaru

Uaru amphiacanthoides

🐠Family Group
Green Fire Tetra
Characins
Uaru
Cichlids - South American
Temperament
Green Fire Tetra
Peaceful (2/10)
Uaru
Mostly Peaceful (4/10)
Temperature
✗ No overlap
Green Fire Tetra
20–26°C
Uaru
27–30°C
pH Range
✓ Compatible
Green Fire Tetra
6.5–7.5
Uaru
5–7
Hardness (dGH)
✓ Compatible
Green Fire Tetra
2–15
Uaru
1–8
Water Type
✓ Compatible
Green Fire Tetra
Freshwater Only
Uaru
Freshwater Only
Flow Preference
✓ Compatible
Green Fire Tetra
Moderate
Uaru
Low
Min Tank Volume
Combined: 400 L
Green Fire Tetra
55 L
Uaru
400 L
Swimming Level
Shared: 1 zone
Green Fire Tetra
MiddleTop
Uaru
MiddleBottom
🏷️Behavior Tags
Green Fire Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Uaru
Plant DestroyerShy / Slow Moving (Easily Stressed)Shrimp Eater
Stocking calculator

Can your tank handle Green Fire Tetra and Uaru?

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
Uaru
Test both in my tank

Behaviour & Temperament

Green Fire Tetra is a peaceful species (2/10), while Uaru is generally mild-mannered (4/10). This modest difference means Uaru may occasionally assert dominance over Green Fire Tetra.

Green Fire Tetra and Uaru 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. Shrimp eaters may also prey on very small nano fish.

Water Parameters

There is no temperature overlap between Green Fire Tetra (20–26°C) and Uaru (27–30°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 6.5 and 7. 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 Green Fire Tetra and Uaru together, plan for an aquarium of at least 400 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: Plants - Densely covered, Driftwood (Digestion/Hiding), Sand (Sifters). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Uaru is a plant destroyer, which conflicts with Green Fire Tetra'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

Green Fire Tetra and Uaru 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 Uaru.

Diet & Feeding

Feeding time deserves special attention with this pairing. Uaru 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 Uaru live together?

No. This combination is not recommended. Key incompatibilities — such as non-overlapping temperature ranges — make cohabitation unsafe.

What size tank do Green Fire Tetra and Uaru need?

A minimum of 400 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 Green Fire Tetra and Uaru together?

Unfortunately, there is no temperature range that satisfies both species. Green Fire Tetra requires 20–26°C, while Uaru needs 27–30°C.

Are Green Fire Tetra or Uaru aggressive?

Green Fire Tetra is peaceful (2/10) and Uaru is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Green Fire Tetra and Uaru need?

Both species overlap in the 6.5–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
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