Can Common Pleco (Amazon Sailfin) and Silver Arowana Live Together?

Common Pleco (Amazon Sailfin) is a generally mild-mannered species (4/10), while Silver Arowana is moderately assertive (6/10). This modest difference means Silver Arowana may occasionally assert dominance over Common Pleco (Amazon Sailfin).

In terms of spatial distribution, Common Pleco (Amazon Sailfin) prefers the Bottom (Substrate) zone, whereas Silver Arowana 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.

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

Worth noting: Common Pleco (Amazon Sailfin) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Silver 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 Common Pleco (Amazon Sailfin) and Silver Arowana 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 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 4–12 dGH. Regular testing will ensure conditions stay within this range.

To house Common Pleco (Amazon Sailfin) and Silver Arowana 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: Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). 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.