Can Iridescent Shark and Spotted Hillstream Loach Live Together?

Iridescent Shark is a generally mild-mannered species (3/10), while Spotted Hillstream Loach is peaceful (2/10). This modest difference means Iridescent Shark may occasionally assert dominance over Spotted Hillstream Loach.

In terms of spatial distribution, Iridescent Shark prefers the Middle (Open Water) zone, whereas Spotted Hillstream Loach occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Iridescent Shark is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 22°C and 24°C. Aim for the midpoint of this range (around 23.0°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 2–12 dGH. Regular testing will ensure conditions stay within this range.

To house Iridescent Shark and Spotted Hillstream Loach together, plan for an aquarium of at least 2000 litres with a minimum length of 250 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). 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.

Iridescent Shark and Spotted Hillstream Loach work best when the tank gives each fish enough room to use its preferred level of the aquarium and enough cover to avoid constant visual contact. The score matters, but the real-world success usually comes from matching their pace, keeping water stable, and resisting the urge to crowd the tank just because the pair looks safe on paper.