Can Asian Arowana and Asian Upside Down Catfish Live Together?

Both Asian Arowana and Asian Upside Down Catfish are semi-aggressive species with an aggression score of 8/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Both Asian Arowana and Asian Upside Down Catfish are highly aggressive, increasing the risk of violent confrontations.

In terms of spatial distribution, Asian Arowana prefers the Top (Surface) zone, whereas Asian Upside Down Catfish occupies the Middle (Open Water) and Bottom (Substrate) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: Asian Upside Down Catfish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Asian Arowana 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 Asian Arowana and Asian Upside Down Catfish to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

The safe temperature window for both species falls between 26°C and 27°C. Aim for the midpoint of this range (around 26.5°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 5–12 dGH. Regular testing will ensure conditions stay within this range.

To house Asian Arowana and Asian Upside Down Catfish together, plan for an aquarium of at least 1000 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.

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), Driftwood (Digestion/Hiding). 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.

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Asian Arowana and Asian Upside Down Catfish need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.