Red Rainbowfish

Glossolepis incisus

Also known as: Salmon-red rainbowfish, New Guinea red rainbowfish, Irian Jaya rainbowfish

Water Parameters

• Temperature: 24–28°C
• pH: 7–8.5
• Hardness (GH): 143–357 ppm (8–20 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

The most intensely-coloured of the larger rainbowfish, the red rainbow is a deep-bodied, almost arched fish from Lake Sentani in West Papua, in which dominant males develop a saturated salmon-to-brick red that few freshwater fish can match. As with all rainbowfish the colour is the reward for patience and proper keeping: juveniles and shop fish are a forgettable silvery-brown, and only a mature male in a group, in hard water, well-fed and competing for females, turns that remarkable red. They are hardy, active, long-lived, and well-suited to the hard, alkaline tap water common across Australia, asking mainly for swimming length, a group, and time. A planted tank with open swimming lanes and a dark background shows the colour to its best. A spectacular large-tank centrepiece and a fine companion for the boesemani and native rainbows already in a hard-water community.

Tankmates

A large, peaceful, active schooling fish that needs a group of at least six, in which the males compete and colour up; a lone or paired red rainbow is a drab, washed-out silver-brown, while a settled group of mature males is a deep glowing salmon-red. Its size and constant activity call for a long tank and similarly-sized, non-aggressive tankmates: other rainbowfish, congo tetras, denison barbs, larger peaceful catfish, and clown loaches. Very small nano fish and shrimp are out of place and may be eaten or simply outpaced at feeding. Its hard-water preference makes it an excellent match for much of Australia's tap supply. Avoid fin-nippers and timid slow species. Like most rainbows it is a jumper, so a covered tank is wise.

Compatible with

• Boeseman's Rainbowfish
• Congo Tetra
• Denison Barb
• Bristlenose Pleco
• Clown Loach
• Silver Dollar

Avoid keeping with

• Betta
• Ember Tetra
• Chili Rasbora
• Cherry Shrimp
• Fin Nippers

Common Problems

• dull colour in small groups or undersized tanks
• slow colour development mistaken for poor stock
• jumping from open tanks
• ich

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20