Can Amazon Puffer and Betta Macrostoma Live Together?

Amazon Puffer is a generally mild-mannered species (3/10), while Betta Macrostoma is moderately assertive (6/10). This modest difference means Betta Macrostoma may occasionally assert dominance over Amazon Puffer.

Amazon Puffer and Betta Macrostoma both frequent the Middle (Open Water), Bottom (Substrate), and Top (Surface) 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.

Worth noting: Amazon Puffer is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Amazon Puffer 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 Amazon Puffer and Betta Macrostoma 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. 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 25°C. Aim for the midpoint of this range (around 23.5°C) for optimal comfort.

Both fish can tolerate a pH between 5.5 and 6. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 4–5 dGH. Regular testing will ensure conditions stay within this range.

To house Amazon Puffer and Betta Macrostoma together, plan for an aquarium of at least 80 litres with a minimum length of 75 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: Sand (Sifters), Driftwood (Digestion/Hiding), Plants - Densely covered, Shells (Breeding/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.

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Amazon Puffer and Betta Macrostoma 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.