What size tank does a Australian Rainbowfish need?

Australian Rainbowfish needs a minimum of 20 gallons, with 30 gallons recommended. They are middle swimmers. Keep in groups of 6+.

Is Australian Rainbowfish good for beginners?

Australian Rainbowfish is rated "beginner" difficulty (1/5). Great for beginners.

What fish are compatible with Australian Rainbowfish?

Australian Rainbowfish is peaceful. Compatible tank mates include other peaceful fish with similar water parameters (pH 7-8, temp 68-77°F).

Australian Rainbowfish

Melanotaenia fluviatilis

Family: Melanotaeniidae • Origin: Various

Australian Rainbowfish (Melanotaenia fluviatilis) is a peaceful rainbow reaching 4 inches. Keep in groups of 6+. Minimum tank size: 20 gallons.

Min Tank

20 gal

Max Size

Temperature

68-77°F

7-8

Lifespan

6 years

School Size

Swim Level

middle

Hardness

5-15 dGH

peacefulbeginneromnivoreschooling

Is Australian Rainbowfish Right for Your Tank?

Australian Rainbowfish is an excellent choice for beginners — rated "beginner" difficulty (1/5). They're hardy, forgiving of minor water parameter fluctuations, and generally easy to feed. A 20-gallon tank minimum is standard — most community setups will accommodate them.

With a peaceful temperament, Australian Rainbowfish makes a great community fish. They coexist well with other non-aggressive species of similar size. This is a schooling species — keep at least 6 together, or they may become stressed and display abnormal behavior. Expected lifespan: 6 years with proper care.

Common Mistakes with Australian Rainbowfish

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Keeping fewer than 6 together

Australian Rainbowfish is a schooling species — they need a group of at least 6 to feel secure. Lone or paired individuals become stressed, hide constantly, and may develop health issues or aggression.

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Putting them in a tank under 20 gallons

Many beginners underestimate tank size needs. Australian Rainbowfish requires at least 20 gallons — ideally 30. Cramped tanks lead to stunted growth, aggression, and poor water quality.