The betta fish (Betta splendens) is one of the most beautiful and most misunderstood fish in the hobby. Sold in tiny cups, marketed as low-maintenance, and kept in conditions that would horrify any aquarist, yet betta fish, given proper care, are intelligent, personable fish that can live 4–5 years and recognise their owners.
This guide covers everything you need to keep a betta healthy: tank size, water parameters, filtration, feeding, and the most common mistakes that cut their lifespan short.
Quick-Reference Care Card
Tank Size: Why the Bowl is Killing Your Betta
The single most damaging myth in betta keeping is that they can live happily in a bowl or vase. In the wild, bettas inhabit shallow rice paddies and ponds, large, open bodies of water, not 1-litre containers.
Minimum: 20 litres (5 gallons). Anything smaller makes stable water chemistry nearly impossible. Small volumes amplify every ammonia spike, temperature swing, and pH crash. A 10-litre tank can go from safe to lethal within hours of a heater fluctuation or missed feeding.
Cold water (below 22°C) slows their metabolism and suppresses immunity. Ammonia from un-cycled tanks burns their gills. Temperature swings without a heater cause chronic stress. These are the real killers, not old age.
Water Parameters and Filtration
Bettas breathe air from the surface using a labyrinth organ, which makes them tolerant of low-oxygen water, but this is often misunderstood as tolerance for bad water. They are not tolerant of ammonia, nitrite, or cold water.
- Temperature: 24–28°C. A heater is mandatory in most homes, especially in winter. Temperature below 22°C = immunosuppression.
- pH: 6.5–7.5. Bettas are flexible here; stability matters more than the exact number.
- Ammonia & nitrite: Must be 0 ppm at all times. Cycle your tank fully before adding a betta.
- Nitrate: Keep below 20 ppm with weekly water changes of 25–30%.
Filter flow: Bettas have long, delicate fins and don't like strong currents. Use a sponge filter or set your filter's output to low. If your betta is being pushed around the tank, the flow is too high.
Feeding Betta Fish
Bettas are obligate carnivores. Their upturned mouth is designed to snatch insects from the water surface, not eat plant-based flake food.
- Best foods: High-quality betta pellets (check that the first ingredient is fish or shrimp), frozen/live bloodworms, brine shrimp, daphnia.
- Frequency: 1–2 small feedings per day. Feed only what they consume in 2 minutes.
- One fast day per week prevents constipation and bloat, one of the most common causes of swim bladder problems.
Bettas' stomachs are the size of their eye. Uneaten food decomposes into ammonia within hours. Feed less than you think you should, if the betta is actively hunting and cleaning the surface, you're feeding correctly.
Tank Mates: Who Can Live with a Betta?
| Species | Compatibility | Notes |
|---|---|---|
| Corydoras catfish | Good | Bottom dwellers, ignored by bettas |
| Neon / ember tetras | Cautious | Some bettas nip tetras; test with individual fish |
| Amano / cherry shrimp | Cautious | Betta may eat small shrimp; snail-sized cherry shrimp safer |
| Nerite / mystery snails | Good | Ignored by most bettas; great algae cleaners |
| Male guppies | Avoid | Flowing tails trigger betta aggression |
| Another male betta | Never | Will fight to the death |
| Gouramis | Avoid | Same family, betta will attack |
Frequently Asked Questions
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