Red Phantom Tetra

Hyphessobrycon sweglesi

Also known as: Red phantom, Swegles tetra

Water Parameters

• Temperature: 22–27°C
• pH: 5–7
• Hardness (GH): 18–143 ppm (1–8 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 rosy-red twin of the black phantom tetra, a delicate, translucent fish washed in orange-red with a black shoulder spot and, in males, a taller dorsal fin used in gentle display. Slightly more demanding than its black cousin, it wants soft, slightly acidic, warm water to show its best colour, so it suits a soft-water or blackwater-style planted tank and looks muted in hard Australian tap water without treatment. Peaceful and undemanding of tankmates, it schools loosely in the mid-water and pairs superbly with cardinal and rummynose tetras in a dimly-lit, planted community. Keep a group of at least six, ideally with several males, and add it to a mature, stable tank rather than a freshly set-up one.

Tankmates

A soft-water schooler that pairs beautifully with cardinal and rummynose tetras in a dimly-lit, planted, blackwater-style tank, and with its black phantom cousin. Prefers softer, more acidic water than the black phantom, and its colour mutes in hard Australian tap water without treatment. Gentle with adult shrimp and small tankmates. Keep a group of at least six, ideally with several males, and add it to a mature tank rather than a new one. Avoid fin-nippers and large fish.

Compatible with

• Cardinal Tetra
• Neon Tetra
• Black Phantom Tetra
• Rummynose Tetra
• Harlequin Rasbora
• Bronze Corydoras
• German Blue Ram
• Otocinclus
• Cherry Shrimp

Avoid keeping with

• Betta
• Tiger Barb
• Serpae Tetra
• Fin Nippers
• Large Cichlids

Common Problems

• muted colour in hard, alkaline water
• sensitivity in new or unstable tanks
• reduced display in groups with too few males
• ich

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