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Rainbowfish from Australia, New Guinea and Indonesia are peaceful, very active schooling fish whose colors intensify as they mature and when males display to each other. A well-kept group is one of the most striking sights in a community aquarium.
They are fast swimmers that use the middle and upper levels of the tank, so length matters more than height. Most species grow to 3-4 inches (8-10 cm) and need a group of at least 6, ideally with more females than males, in a tank of 40-55 gallons (150-200 L) or larger. Neon dwarf rainbows and forktail blue-eyes are smaller and suit more modest tanks.
- Water: clean, well-oxygenated water at 74-80 °F (23-27 °C), slightly alkaline for most Australian and New Guinea species.
- Tank mates: other active, peaceful fish of similar size: larger tetras, corydoras, bristlenose plecos and peaceful barbs.
- Diet: omnivores; a varied menu with quality flakes and frozen foods brings out color.
Leave open swimming space in front, plant the back and sides, and keep a lid on: they can jump. Juveniles in stores often look dull; give them time and good care and they color up.
Rainbowfish
| Species | Min. liters | Size | Temp. | Difficulty |
|---|---|---|---|---|
 Boeseman's rainbowfish Melanotaenia boesemani | 53 gal (200 L) | 3.9 in (10 cm) | 77–84 °F (25–29 °C) | Moderate |
 Celebes rainbowfish Marosatherina ladigesi | 26 gal (100 L) | 2.8 in (7 cm) | 75–82 °F (24–28 °C) | Moderate |
 Dwarf neon rainbowfish Melanotaenia praecox | 32 gal (120 L) | 2.4 in (6 cm) | 75–82 °F (24–28 °C) | Easy |
 Eastern rainbowfish (splendid rainbowfish) Melanotaenia splendida | 53 gal (200 L) | 4.3 in (11 cm) | 72–82 °F (22–28 °C) | Easy |
 Forktail blue-eye Pseudomugil furcatus | 16 gal (60 L) | 2 in (5 cm) | 75–82 °F (24–28 °C) | Moderate |
 Red rainbowfish Glossolepis incisus | 66 gal (250 L) | 4.7 in (12 cm) | 72–79 °F (22–26 °C) | Moderate |
No species match those filters.