Can Chinese Algae Eater (CAE) and Gardner's Killifish Live Together?

Chinese Algae Eater (CAE) is a semi-aggressive species (8/10), while Gardner's Killifish is generally mild-mannered (4/10). This notable difference means Chinese Algae Eater (CAE) may occasionally assert dominance over Gardner's Killifish.

In terms of spatial distribution, Chinese Algae Eater (CAE) prefers the Bottom (Substrate) zone, whereas Gardner's Killifish occupies the Top (Surface) and Middle (Open Water) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

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

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Chinese Algae Eater (CAE) and Gardner's Killifish to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

The safe temperature window for both species falls between 22°C and 26°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

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 5–10 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Chinese Algae Eater (CAE) and Gardner's Killifish together, plan for an aquarium of at least 240 litres with a minimum length of 120 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: Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Plants - Floating, Plants - lighly covered. Meeting these requirements will help both species thrive.

Chinese Algae Eater (CAE) prefers High (River/Stream) flow while Gardner's Killifish needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.