Can Silver Arowana and Threadfin Rainbowfish Live Together?
Silver Arowana and Threadfin Rainbowfish are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.
At a Glance
Behaviour & Temperament
Silver Arowana is a moderately assertive species (6/10), while Threadfin Rainbowfish is peaceful (1/10). This notable difference means Silver Arowana may occasionally assert dominance over Threadfin Rainbowfish.
Silver Arowana and Threadfin Rainbowfish both frequent the Top (Surface) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.
There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..
Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion.
Worth noting: Silver Arowana is a known jumper, so a tight-fitting lid is essential.
Water Parameters
The safe temperature window for both species falls between 24°C and 29°C. Aim for the midpoint of this range (around 26.5°C) for optimal comfort.
Both fish can tolerate a pH between 6 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 1–12 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.
Tank Setup
To house Silver Arowana and Threadfin Rainbowfish together, plan for an aquarium of at least 1200 litres with a minimum length of 240 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: Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Plants - Floating. 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.
Find the right tank equipment
Browse tanks, décor, and equipment suited for this setup.
Frequently Asked Questions
Can Silver Arowana and Threadfin Rainbowfish live together?▾
No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.
What size tank do Silver Arowana and Threadfin Rainbowfish need?▾
A minimum of 1200 litres (tank length at least 240 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.
What water temperature is best for Silver Arowana and Threadfin Rainbowfish together?▾
Keep the aquarium between 24°C and 29°C. A target of around 26.5°C sits comfortably within both species' preferred ranges.
Are Silver Arowana or Threadfin Rainbowfish aggressive?▾
Silver Arowana is moderately assertive (6/10) and Threadfin Rainbowfish is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.
What pH do Silver Arowana and Threadfin Rainbowfish need?▾
Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.
How do I manage Silver Arowana's territorial behaviour?▾
Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Silver Arowana space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.
Related Comparisons
Silver Arowana & African Butterfly Fish
·
Silver Arowana & Banded Archerfish (Brackish)
·
Silver Arowana & Black Ghost Knifefish
·
Silver Arowana & Clown Knifefish
·
Silver Arowana & Fire Eel
·
Silver Arowana & Florida Gar
·
Threadfin Rainbowfish & Boeseman's Rainbowfish
·
Threadfin Rainbowfish & Dwarf Neon Rainbowfish (Praecox)
·
Threadfin Rainbowfish & Forktail Blue-eye
·
Threadfin Rainbowfish & Gertrude's Spotted Blue-eye
·
Threadfin Rainbowfish & Red Rainbowfish
·
Threadfin Rainbowfish & Turquoise Rainbowfish
·