Can Australian Smelt and Flowerhorn Cichlid Live Together?

Australian Smelt is a peaceful species (1/10), while Flowerhorn Cichlid is highly aggressive (10/10). This notable difference means Flowerhorn Cichlid may occasionally assert dominance over Australian Smelt.

Large aggression gap (9 points) between Australian Smelt and Flowerhorn Cichlid increases stress risk for the more peaceful fish.

Australian Smelt and Flowerhorn Cichlid both frequent the Middle (Open Water) 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.

Worth noting: Australian Smelt is a known jumper, so a tight-fitting lid is essential.

There is no temperature overlap between Australian Smelt (15–24°C) and Flowerhorn Cichlid (26–30°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 7.4 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 9–20 dGH. Regular testing will ensure conditions stay within this range.

To house Australian Smelt and Flowerhorn Cichlid together, plan for an aquarium of at least 280 litres with a minimum length of 120 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: Plants - lighly covered, Smooth Gravel (Sensitive Barbels), Sand (Sifters). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Flowerhorn Cichlid is a plant destroyer, which conflicts with Australian Smelt's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Australian Smelt and Flowerhorn Cichlid 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.