Can Assassin Snail and Moonlight Gourami Live Together?

Assassin Snail is a peaceful species (2/10), while Moonlight Gourami is generally mild-mannered (3/10). This modest difference means Moonlight Gourami may occasionally assert dominance over Assassin Snail.

In terms of spatial distribution, Assassin Snail prefers the Bottom (Substrate) zone, whereas Moonlight Gourami occupies the Top (Surface) and Middle (Open Water) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Moonlight Gourami is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 25°C and 28°C. Aim for the midpoint of this range (around 26.5°C) for optimal comfort.

Both fish can tolerate a pH between 7 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 8–15 dGH. Regular testing will ensure conditions stay within this range.

To house Assassin Snail and Moonlight Gourami together, plan for an aquarium of at least 150 litres with a minimum length of 90 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: Sand (Sifters), Plants - Densely covered, Plants - Floating. Meeting these requirements will help both species thrive.

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

Assassin Snail and Moonlight Gourami 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.