Can Amazon Leaf Fish and Black Pacu Live Together?

Amazon Leaf Fish is a peaceful species (2/10), while Black Pacu is generally mild-mannered (4/10). This modest difference means Black Pacu may occasionally assert dominance over Amazon Leaf Fish.

Amazon Leaf Fish and Black Pacu 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Amazon Leaf Fish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Black Pacu 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.

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 6.8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–8 dGH. Regular testing will ensure conditions stay within this range.

To house Amazon Leaf Fish and Black Pacu together, plan for an aquarium of at least 4560 litres with a minimum length of 300 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: Leaf Litter/Blackwater, Plants - Densely covered, Driftwood (Digestion/Hiding), Plants - Floating, Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Black Pacu is a plant destroyer, which conflicts with Amazon Leaf Fish's requirement for live plants. Compromise where possible or prioritise the more critical need.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Feeding time deserves special attention with this pairing. Black Pacu is an aggressive eater that may prevent Amazon Leaf Fish from getting enough food.

Because Black Pacu is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Amazon Leaf Fish receives an adequate share.