Why is my Turquoise Rainbowfish losing its colour?

Colour loss is commonly caused by stress, poor water quality, or an inappropriate diet. Ensure your water is adequately hard and alkaline (pH 7.5+), the fish is kept in a group of at least six, and they are fed a varied diet including frozen foods.

Can I keep Turquoise Rainbowfish with soft water fish like Discus?

It is not recommended. Turquoise Rainbowfish require hard, alkaline water and cooler temperatures (20-25°C), which completely contrasts with the soft, acidic, and warm conditions demanded by Discus.

How large a tank do I need for a shoal?

Because they are incredibly active swimmers, a tank length of at least 100cm (approximately 120 litres) is considered the absolute minimum for a group of six, though larger is always better.

At what age do they show their full blue colouration?

Juveniles are typically a plain silver. They begin to develop their turquoise colouration at around 5-6 cm in length, which usually takes 6 to 8 months of age, with full adult vibrancy appearing after a year.

Will they jump out of the aquarium?

Yes, rainbowfish are known to be strong jumpers, particularly if startled or when displaying during feeding. A tight-fitting lid or cover glass is essential to prevent accidents.

AI-generated illustration for OneShoal

FreshwaterTropicalIntermediate

Turquoise Rainbowfish

Melanotaenia lacustris

The Turquoise Rainbowfish is a stunning, active shoaling species famed for its shimmering blue hues and preference for hard, alkaline water.

List this species for sale Find Turquoise Rainbowfish near me

Ideal Conditions

Temperature: 20 – 25 °C
pH range: 7.5 – 8.5
Hardness: 10 – 20 dGH
Adult size: 10 – 12 cm
120L minimum, 100cm+ tank length required: 120 litres+
Lifespan: 5 – 8 years
Diet: Omnivorous
Water flow: moderate
Preferred setup: Planted with ample open swimming space

About the Turquoise Rainbowfish

Hailing exclusively from the pristine waters of Lake Kutubu in Papua New Guinea, the Turquoise Rainbowfish is one of the aquarium hobby's most coveted freshwater species. Mature specimens, particularly males, develop a spectacular, high-backed profile and a mesmerising metallic blue colouration that can shift in intensity depending on their mood or the lighting. Due to their active nature, they demand a spacious aquarium to thrive. Kept in appropriate numbers, they create a breathtaking, fast-moving display that easily becomes the focal point of a large community setup.

Find Turquoise Rainbowfish

Search current listings in your chosen area. If none are available, save an alert and we’ll let you know when a match is listed.

Find locally Check compatibility Add to a Setup

Availability alerts only use public sale listings. Adding this species to a Setup updates your private records.

Is it right for your tank?

Check Turquoise Rainbowfish against a habitat you already keep. We compare water type, temperature, pH, adult size, group needs and everything living there.

Where Turquoise Rainbowfish comes from

Native range

Lake Kutubu, Soro River

Countries / regions

Papua New Guinea

Habitat

Clear, still, highly alkaline lake waters with dense patches of aquatic vegetation and submerged logs.

Endemic to Lake Kutubu and its immediate outlet; currently listed as Vulnerable on the IUCN Red List due to habitat degradation.

Similar species

Boeseman's Rainbowfish
Melanotaenia boesemani
Dwarf Neon Rainbowfish
Melanotaenia praecox
Red Rainbowfish
Glossolepis incisus

We’re adding more full species guides as the catalogue grows.

Compatible tank mates

Reviewed guidance based on this species' recorded traits.

View all compatibility

Boeseman's Rainbowfish
Melanotaenia boesemani
Shares identical water parameters and active shoaling behaviour, providing a spectacular colour contrast.
Great
Congo Tetra
Phenacogrammus interruptus
A robust, active tetra that thrives in spacious setups and will not be outcompeted during feeding.
Great
Bronze Corydoras
Corydoras aeneus
Occupies the bottom levels out of the rainbowfish's way and appreciates similar water conditions.
Great
Cherry Shrimp
Neocaridina davidi
Adults are generally safe in a well-planted tank, but shrimplets will almost certainly be hunted and eaten by mature rainbowfish.
Compatible with caution
Siamese Fighting Fish (Betta)
Betta splendens
The rapid movements and boisterous nature of the rainbowfish will cause significant stress to a slow-moving Betta.
Not recommended

Current marketplace listings

Checking the marketplace…

See all Turquoise Rainbowfish listings

Public Wanted requests

No open requests for Turquoise Rainbowfish in this market yet.

Looking for Turquoise Rainbowfish?

Search current listings near you, or post a wanted request so local sellers know what you’re looking for.

Search Turquoise Rainbowfish listings Post a wanted request