Care guide, husbandry, breeding, disease, and sourcing intelligence on Australian Rainbowfish - written by the Fast Aquatics editorial team.
Australian Rainbowfish at a glance
Adult size: 4 inches · Min tank/pond: 30 gallons · Difficulty: beginner · Diet: omnivore · Lifespan: 5-8 years.
Australian Rainbowfish (Melanotaenia fluviatilis) is a popular freshwater fish in the aquarium and pond hobby. Hardy and forgiving when given proper water chemistry.
Where Australian Rainbowfish comes from
Australian Rainbowfish (Melanotaenia fluviatilis) is native to specific tropical and subtropical freshwater systems. Captive-bred specimens at most LFS come from generations of farmed stock and are generally hardier and more colorful than wild-caught equivalents.
Australian Rainbowfish tank size and setup
Australian Rainbowfish requires a minimum of 30 gallons for healthy adults. The minimum is based on 4 inches adult size and territorial range. Plan a tank sized for adult footprint, HOB or canister filter rated 4-6x volume, dechlorinated water, appropriate temperature heater, and stocking-appropriate hardscape.
Water parameters for Australian Rainbowfish
Australian Rainbowfish prefers freshwater parameters: temperature 74-80°F, pH 6.5-7.5, GH 4-12 dGH, KH 3-8 dKH, ammonia + nitrite 0 ppm, nitrate under 20 ppm. Use dechlorinator on every water change.
What Australian Rainbowfish eats
Australian Rainbowfish is a omnivore. Provide a varied diet of pellets, frozen foods, and supplemental greens. Feed twice daily in small portions. Browse our food guides for product recommendations.
Australian Rainbowfish tankmates and compatibility
Australian Rainbowfish works in community tanks with peaceful species in similar size class. Avoid mixing aggressive with passive species.
Australian Rainbowfish adult size and lifespan
Australian Rainbowfish reaches 4 inches at adulthood with a captive lifespan of 5-8 years with proper care.
Can you breed Australian Rainbowfish?
Australian Rainbowfish can be bred in dedicated breeding tanks with appropriate setup and water-chemistry triggers. Research the species-specific breeding requirements before attempting.
Common Australian Rainbowfish diseases and problems
Australian Rainbowfish is susceptible to standard freshwater diseases (ich, columnaris, fin rot, bacterial infections). Quarantine new Australian Rainbowfish for 4 weeks before adding to display.
Where to buy Australian Rainbowfish online
Australian Rainbowfish is sold at LFS, online retailers, and direct from breeders. Browse live Australian Rainbowfish from vetted Fast Aquatics vendors with carrier-tracked overnight shipping, climate-aware hold logic, and a 4-hour DOA window with photo-evidence claims.
Related freshwater species you might also keep
Other species in the same category with care profiles on Fast Aquatics. Click any name for the full husbandry breakdown.
Australian Rainbowfish taxonomy and care recommendations cross-checked against the following authoritative references and our internal vendor + breeder database.