Can Red Phantom Tetra and Uaru Live Together?
Red Phantom 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
Can your tank handle Red Phantom 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.
Behaviour & Temperament
Red Phantom Tetra is a peaceful species (1/10), while Uaru is generally mild-mannered (4/10). This modest difference means Uaru may occasionally assert dominance over Red Phantom Tetra.
Red Phantom 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 Red Phantom Tetra (20–24°C) and Uaru (27–30°C). This fundamental mismatch makes long-term cohabitation impractical.
Both fish can tolerate a pH between 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 1–8 dGH. Regular testing will ensure conditions stay within this range.
Tank Setup
To house Red Phantom 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, Plants - Floating, Leaf Litter/Blackwater, 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 Red Phantom Tetra'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
Red Phantom 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 Red Phantom 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 Red Phantom Tetra.
Frequently Asked Questions
Can Red Phantom 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 Red Phantom 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 Red Phantom Tetra and Uaru together?
Unfortunately, there is no temperature range that satisfies both species. Red Phantom Tetra requires 20–24°C, while Uaru needs 27–30°C.
Are Red Phantom Tetra or Uaru aggressive?
Red Phantom Tetra is peaceful (1/10) and Uaru is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.
What pH do Red Phantom Tetra and Uaru need?
Both species overlap in the 5–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.
Shared setup supplies
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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?
- Contact the editorial team
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