Can Leopoldi Stingray (Black Diamond) and Red Phantom Tetra Live Together?

Leopoldi Stingray (Black Diamond) is a moderately assertive species (5/10), while Red Phantom Tetra is peaceful (1/10). This notable difference means Leopoldi Stingray (Black Diamond) may occasionally assert dominance over Red Phantom Tetra.

In terms of spatial distribution, Leopoldi Stingray (Black Diamond) prefers the Bottom (Substrate) zone, whereas Red Phantom Tetra occupies the Middle (Open Water) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

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

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.

There is no temperature overlap between Leopoldi Stingray (Black Diamond) (26–30°C) and Red Phantom Tetra (20–24°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 6 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 3–10 dGH. Regular testing will ensure conditions stay within this range.

To house Leopoldi Stingray (Black Diamond) and Red Phantom Tetra together, plan for an aquarium of at least 1135 litres with a minimum length of 240 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: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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.

Leopoldi Stingray (Black Diamond) and Red Phantom Tetra 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.

Feeding time deserves special attention with this pairing. Leopoldi Stingray (Black Diamond) is a known shrimp eater and may prey on small invertebrates or nano fish like Red Phantom Tetra.