The Blue Emperor Tetra 3.5–4cm is a slightly smaller, more refined emperor tetra species that brings subtle colour and constant movement to community aquariums. In softer, side‑lit or moderately lit tanks, males display a beautiful luminous blue to mauve sheen, while females show softer tones and a more rounded body shape.
Because they stay relatively small and have a peaceful temperament, Blue Emperor Tetra 3.5–4cm are an excellent choice for planted aquariums, aquascapes and calm community setups.
Blue Emperor Tetra 3.5–4cm – Key Features
- Slightly smaller species compared to other emperor tetras
- Size at sale: approximately 3.5–4cm
- Males show luminous blue to mauve body colour in the right lighting
- Active, peaceful schooling fish – ideal for community tanks
- Looks fantastic in planted aquariums with softer, side or ambient lighting
If you want a schooling fish with elegant colour rather than neon intensity, Blue Emperor Tetra 3.5–4cm is a great option.
Tank Requirements for Blue Emperor Tetra
Blue Emperor Tetras are active, mid‑water schooling fish that appreciate space and company:
- Tank size: from 60cm / 2ft upwards for a small group
- Group size: keep in groups of 6+, ideally 10+ for best behaviour and colour
- Décor: plants, driftwood and open swimming space
- Lighting: avoid very harsh, bright overhead light – side light or moderate lighting helps their colours show better
- Filtration: gentle to moderate flow with good oxygenation
A planted, slightly shaded aquarium helps Blue Emperor Tetra 3.5–4cm feel secure and display their best colours.
Water Parameters (Guide Only)
Blue emperors are fairly adaptable but do best in clean, stable water:
- Temperature: around 23–27°C
- pH: roughly 6.0–7.5 (slightly acidic to neutral)
- Hardness: soft to medium hardness
- Ammonia & Nitrite: 0 ppm
- Nitrate: kept low with regular water changes
Consistent maintenance and avoiding sudden parameter swings are key for long‑term success with Blue Emperor Tetra 3.5–4cm.
Feeding Blue Emperor Tetra 3.5–4cm
Blue Emperor Tetras are omnivores and very easy to feed:
- Staple foods:
- Quality micro‑pellets or small tropical pellets
- Fine flake foods designed for community fish
- Extras and treats:
- Frozen or live foods such as daphnia, brine shrimp and bloodworms (in moderation)
Feed small amounts 1–2 times daily, ensuring all food is consumed within a few minutes. A varied diet keeps Blue Emperor Tetra 3.5–4cm in good condition and helps males show their best colour.
Behaviour and Tank Mates
Blue Emperor Tetra 3.5–4cm are active, peaceful schooling fish:
- Behaviour: mid‑water swimmers that look best in a group
- Temperament: generally peaceful and community‑friendly
- Display: males may display to each other, showing off their blue to mauve colours
Suitable tank mates include:
- Other peaceful tetras and rasboras
- Corydoras catfish and smaller peaceful bottom dwellers
- Small, calm gourami or dwarf cichlids (with care and space)
- Shrimp and snails may be suitable, though very small shrimplets can be at risk
Avoid large, aggressive or fin‑nipping fish that may stress Blue Emperor Tetras.
