Congo Tetra
Phenacogrammus interruptus
Quick Facts
- Adult size: 6-8.5 cm (2.4-3.3 inches)
- Minimum tank size: 150 litres (40 gallons)
- Lifespan: 3–5 years
- Temperament: peaceful
- Swimming level: middle
- Diet: omnivore
- Minimum group size: 6
- Difficulty: intermediate
Water Parameters
- Temperature: 23–28°C
- pH: 6–7.5
- Hardness (GH): 36–179 ppm (2–10 dGH)
Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.
Care Summary
An African characin and one of the most beautiful larger tetras, the males developing iridescent blue, gold, and orange flanks and trailing, feathered fins that no nano tetra can match. Congo tetras are schooling fish that demand both numbers and space: a group of eight or more in a long, planted, dimly-lit tank is a genuine showpiece, while a lonely pair in a bright bare tank is a pale, nervous disappointment. They prefer soft, slightly acidic water and respond to bright open setups by hiding, so aquascaping for security pays off directly in colour and behaviour. Hardy once settled but easily startled, and best added to a mature, established tank. A standout centrepiece for a peaceful soft-water community of adequate size.
Tankmates
A peaceful, soft-water schooling fish that needs a group of at least six to feel secure; in smaller numbers it is shy, skittish, and prone to dashing into the glass when startled. The males' long, flowing, white-edged finnage is a target for fin-nippers, so keep them well away from tiger barbs, serpae tetras, and the like. Their adult size makes them safe with most peaceful community fish but a threat to dwarf shrimp and the smallest nano species. Excellent companions for rainbowfish, peaceful gouramis, corydoras, and dwarf cichlids such as kribs. Give them a planted tank with open swimming space, dark substrate, and subdued lighting to bring out colour and confidence.
Compatible with
- Boeseman's Rainbowfish
- Pearl Gourami
- Bronze Corydoras
- Bristlenose Pleco
- Kribensis
- Rummynose Tetra
- Dwarf Chain Loach
- Bleeding Heart Tetra
- Diamond Tetra
Avoid keeping with
- Betta
- Tiger Barb
- Fin Nippers
- Large Cichlids
- Cherry Shrimp
Common Problems
- shyness and skittishness in groups smaller than 6
- nipped finnage from inappropriate tankmates
- washed-out colour in bright, bare tanks
- jumpiness leading to collisions when startled
Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20