Can Green Spotted Puffer (Brackish) and Uaru Live Together?

Green Spotted Puffer (Brackish) is a highly aggressive species (9/10), while Uaru is generally mild-mannered (4/10). This notable difference means Green Spotted Puffer (Brackish) may occasionally assert dominance over Uaru.

Green Spotted Puffer (Brackish) and Uaru both frequent the Middle (Open Water) and Bottom (Substrate) 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: Aggressive fish may bully and stress shy, slow-moving species.

The safe temperature window for both species falls between 27°C and 28°C. Aim for the midpoint of this range (around 27.5°C) for optimal comfort.

The pH requirements of Green Spotted Puffer (Brackish) (7.5–8.5) and Uaru (5–7) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Green Spotted Puffer (Brackish) needs 12–30 dGH while Uaru requires 1–8 dGH.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together. An aquarium test kit is recommended for monitoring.

To house Green Spotted Puffer (Brackish) and Uaru together, plan for an aquarium of at least 480 litres with a minimum length of 150 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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), Shells (Breeding/Hiding), Driftwood (Digestion/Hiding). 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.