Can Bleeding Heart Tetra and Golden Wonder Killifish Live Together?

Bleeding Heart Tetra is a peaceful species (2/10), while Golden Wonder Killifish is moderately assertive (6/10). This notable difference means Golden Wonder Killifish may occasionally assert dominance over Bleeding Heart Tetra.

In terms of spatial distribution, Bleeding Heart Tetra prefers the Middle (Open Water) zone, whereas Golden Wonder Killifish occupies the Top (Surface) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Golden Wonder Killifish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. 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 22°C and 28°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.2. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Bleeding Heart Tetra and Golden Wonder Killifish together, plan for an aquarium of at least 132 litres with a minimum length of 80 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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, Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Floating. 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.