Can Axelrod's Rainbowfish and Blind Cave Tetra Live Together?

Axelrod's Rainbowfish is a peaceful species (2/10), while Blind Cave Tetra is generally mild-mannered (4/10). This modest difference means Blind Cave Tetra may occasionally assert dominance over Axelrod's Rainbowfish.

Axelrod's Rainbowfish 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.

Worth noting: Axelrod's Rainbowfish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

The safe temperature window for both species falls between 24°C and 25°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–18 dGH. Regular testing will ensure conditions stay within this range.

To house Axelrod's Rainbowfish and Blind Cave Tetra together, plan for an aquarium of at least 150 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - Densely covered, Smooth Gravel (Sensitive Barbels). 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.