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🐟 Rainbowfish care

Dwarf neon rainbowfish

Melanotaenia praecox

easy care
Min tank size 90 L / 20 gal
Temperature 22–28 °C
pH 6.5–7.5
Adult size About 6 cm
Temperament Peaceful, active
Diet Omnivore
Lifespan 3–5 years
Keep in A shoal of six or more

Overview

The dwarf neon rainbowfish (Melanotaenia praecox) is the small, shimmering cousin of the big rainbowfish — a 6 cm shoaler that flashes neon blue in the light, with males wearing red-edged fins. Peaceful, hardy and far more tank-friendly in size than a boesemani, it brings rainbowfish sparkle to medium planted community tanks. All it asks is a proper group and a bit of open water to swim.

Tank & water

A shoal is at home in 90 litres (20–25 gallons) or more, with length for swimming.

  • Temperature: an adaptable 22–28 °C, held with a heater.
  • Water: pH 6.5–7.5 and soft to moderately hard; test with a kit.
  • Planted with open lanes: plant the edges, leave a clear swimming channel down the middle.
  • Filtration: a reliable filter with gentle flow and regular water changes.
Numbers bring colour: in a group of six-plus, males display and flash their best neon. A lone or paired dwarf rainbow stays pale and nervous — always buy a shoal.

Feeding

Dwarf neon rainbowfish are easy omnivores. Feed a quality micro-pellet or flake staple plus frozen or live daphnia, brine shrimp and bloodworm, with some spirulina or vegetable matter. Their upturned mouths take food best from the surface and mid-water. Feed small amounts once or twice a day.

Tankmates

Ideal, peaceful community residents. They mix beautifully with tetras, rasboras, corydoras, peaceful barbs and calm dwarf cichlids such as the Bolivian ram. Avoid large or aggressive fish and fin-nippers. A mixed rainbowfish display alongside boesemani looks superb in a big enough tank. For limits, see how many fish in an aquarium.

Dwarf neon rainbowfish — frequently asked questions

Are dwarf neon rainbowfish good for a community tank?

Yes — they are peaceful, hardy and beautifully coloured, with a shimmering neon-blue body and red fins on males. Kept in a shoal of six or more, they make an excellent, active centrepiece for a planted community and get along with most other calm fish.

How big do dwarf neon rainbowfish get?

Around 6 cm, much smaller than most rainbowfish, which is why they suit tanks from about 90 litres rather than the 200-litre-plus that larger species like the boesemani need. Their modest size makes them a rare rainbowfish option for medium tanks.

Do dwarf neon rainbowfish need to be in a group?

Absolutely. They are shoaling fish that feel secure and colour up only in numbers. A group of six or more reduces stress, encourages males to display and prevents the timid, faded look of fish kept singly or in pairs.

Gear for a dwarf neon rainbowfish tank: tanks · filters · heaters · food · water tests
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