Best Schooling Fish for a Large Freshwater Aquarium
There is nothing quite like watching 30 neon tetras turn as one body in the middle of a planted tank. True schooling fish move together, respond to each other, and create a living, fluid display that no individual fish can replicate. Here are the best schooling fish for large freshwater aquariums in Singapore.
True Schooling vs Shoaling
Not all fish sold as "schooling" fish actually school tightly:
- True schoolers align their bodies and move in coordinated groups (rummy nose tetras, cardinal tetras)
- Shoalers prefer to be near their own species but move independently (most rasboras)
Both are visually impressive in large numbers, but true schoolers create the most dramatic effect.
Best Schooling Fish for Large Tanks
1. Rummy Nose Tetra
The rummy nose tetra is widely considered the tightest-schooling freshwater fish available. Groups of 30 or more move in perfect unison, making lightning-fast direction changes as one unit. Their bright red head and black-and-white tail stripe make them unmistakeable.
Recommended number: 20–50 | Tank: 120+ litres | Temp: 24–28°C | pH: 5.5–7.0
2. Cardinal Tetra
Cardinals are spectacular in large groups — their vivid red and blue bands become a shimmering wall of colour. They are a natural companion for discus and thrive in soft, slightly acidic water.
Recommended number: 15–30 | Tank: 100+ litres | Temp: 23–28°C | pH: 5.5–7.0
3. Harlequin Rasbora
Harlequin rasboras are one of Singapore's most popular aquarium fish. In groups of 15 or more they create a warm, copper-toned shimmer through the mid-water. They are hardy and peaceful, compatible with virtually any community species.
Recommended number: 15–25 | Tank: 80+ litres | Temp: 22–27°C | pH: 6.0–7.5
4. Black Phantom Tetra
Black phantom tetras are elegant silver-and-black fish that school loosely but look stunning in groups of 20 or more. Males regularly display to each other in mock sparring — entertaining but non-violent.
Recommended number: 15–25 | Tank: 80+ litres | Temp: 22–28°C | pH: 6.0–7.5
5. Ember Tetra
Ember tetras are tiny (2 cm) orange fish that drift through planted tanks in loose, glowing clouds. They are ideal for large planted aquariums where you want colour without overwhelming the plant-focused aesthetic.
Recommended number: 20–40 | Tank: 60+ litres | Temp: 23–29°C | pH: 5.5–7.0
6. Chili Rasbora (Boraras brigittae)
Chili rasboras are the smallest species on this list at just 1.5–2 cm, but in groups of 30 or more in a nano-style planted tank they are unforgettable. Their deep crimson colour is among the richest of any freshwater fish.
Recommended number: 25–50 | Tank: 40+ litres | Temp: 22–28°C | pH: 5.0–7.0
How Many Is Enough?
The minimum group sizes below apply to standard tanks. For large display tanks (120+ litres), doubling these numbers transforms the display:
| Species | Minimum | Ideal display |
|---|---|---|
| Rummy nose tetra | 10 | 30–50 |
| Cardinal tetra | 8 | 20–30 |
| Harlequin rasbora | 8 | 15–25 |
| Ember tetra | 10 | 25–40 |
Stocking Tips
- Add your entire school at once to reduce territorial behaviour
- Introduce schooling fish before bottom-dwellers and centrepiece fish
- Reduce other visual competition — schooling fish look best against a clean planted background
Shop our freshwater livestock for all species listed above, available now in Singapore.