Melanotaenia praecox
All the colour of a full-size rainbow in a nano-friendly package: iridescent blue body, neon-red fins. Side-lighting from the front of the hood makes the blue absolutely pop. Schools tightly and tolerates a wider parameter range than its bigger Melanotaenia cousins.
Dwarf Neon Rainbowfish (Melanotaenia praecox) reaches 5–6 cm as an adult and needs a minimum tank of 75 L. Native to Mamberamo River basin, West Papua, it lives in the mid to top water column with a peaceful temperament. Aim for 22–28 °C, pH 6.5–7.5, and 5–15 dGH hardness. Lifespan is 3–5 years with good care. Keep dwarf neon rainbowfish in groups of 6+, yes schoolers need numbers to display natural behaviour. Diet: omnivore, Micro pellets, flake, frozen daphnia and bloodworms. Small upturned mouth, keep food fine. Plant-safe: Yes. Shrimp-safe: Mostly (may eat shrimplets).
Care at a glance
All the colour of a full-size rainbow in a nano-friendly package: iridescent blue body, neon-red fins. Side-lighting from the front of the hood makes the blue absolutely pop. Schools tightly and tolerates a wider parameter range than its bigger Melanotaenia cousins.
By Mike ElmiraUpdated 1 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether dwarf neon rainbowfish fits in your tank.
Mid to Top
Yes
Group of 6+
Melanotaeniidae
Omnivore
Micro pellets, flake, frozen daphnia and bloodworms. Small upturned mouth, keep food fine.
3–5 yrs
Medium
Mamberamo River basin, West Papua
Mamberamo River basin, West Papua
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Dwarf Neon Rainbowfish (Melanotaenia praecox) needs a minimum tank of 75 L. They live in the mid to top water column and should be kept in groups of 6+, so a longer footprint matters more than depth.
Target 22–28 °C, pH 6.5–7.5, and 5–15 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Mostly (may eat shrimplets). Plant safety: Yes.
Dwarf Neon Rainbowfish are omnivore. Micro pellets, flake, frozen daphnia and bloodworms. Small upturned mouth, keep food fine.
On Fin & Stem's 1–5 difficulty scale this species rates 2/5. Forgiving, beginner-friendly once the tank is cycled. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 3–5 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
