Can Hillstream Loach and Peacock Bass Orinocensis Live Together?

Hillstream Loach is a peaceful species (2/10), while Peacock Bass Orinocensis is semi-aggressive (8/10). This notable difference means Peacock Bass Orinocensis may occasionally assert dominance over Hillstream Loach.

Large aggression gap (6 points) between Hillstream Loach and Peacock Bass Orinocensis increases stress risk for the more peaceful fish.

In terms of spatial distribution, Hillstream Loach prefers the Bottom (Substrate) zone, whereas Peacock Bass Orinocensis occupies the Middle (Open Water) and Top (Surface) 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: Peacock Bass Orinocensis is a known jumper, so a tight-fitting lid is essential.

There is no temperature overlap between Hillstream Loach (18–24°C) and Peacock Bass Orinocensis (26–31°C). This fundamental mismatch makes long-term cohabitation impractical.

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 4–15 dGH. Regular testing will ensure conditions stay within this range.

To house Hillstream Loach and Peacock Bass Orinocensis together, plan for an aquarium of at least 750 litres with a minimum length of 200 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus), Sand (Sifters), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with high (river/stream) water movement, so a standard filtration setup rated for the tank volume should suffice.

Hillstream Loach and Peacock Bass Orinocensis are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.