Can Altum Angel and Blind Cave Tetra Live Together?

Altum Angel is a moderately assertive species (5/10), while Blind Cave Tetra is generally mild-mannered (4/10). This modest difference means Altum Angel may occasionally assert dominance over Blind Cave Tetra.

Altum Angel and Blind Cave Tetra 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. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

There is no temperature overlap between Altum Angel (27–32°C) and Blind Cave Tetra (20–25°C). This fundamental mismatch makes long-term cohabitation impractical.

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

Hardness requirements are incompatible: Altum Angel needs 1–5 dGH while Blind Cave Tetra requires 8–20 dGH.

To house Altum Angel and Blind Cave Tetra together, plan for an aquarium of at least 400 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: Sand (Sifters), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Floating, Smooth Gravel (Sensitive Barbels). 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.

Altum Angel and Blind Cave 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. Blind Cave Tetra is an aggressive eater that may prevent Altum Angel from getting enough food.

Because Blind Cave Tetra is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Altum Angel receives an adequate share.