Betta
Betta splendens
Betta fish, also known as Siamese fighting fish, are popular for their striking colors and flowing fins. They are known for their territorial nature, especially males, which can display aggressive behavior towards each other.
Betta splendens exhibits vibrant color variations, including iridescent blues and reds, with long flowing fins and a pronounced, aggressive demeanor.
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Quick Facts
Size
6.5 cm
Temperament
Semi-aggressive
Difficulty
Beginner
Min Tank Size
5 gallons
Lifespan
3-5 years
Origin
Southeast Asia
Diet
Carnivore - protein-rich foods, pellets, and live or frozen foods like bloodworms and brine shrimp
Water Parameters
24-30°C
6-8
5-19 dGH
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Calculate heater sizeCare Notes
- Keep a single Betta in a heated, fully cycled aquarium of 5+ gallons (10+ is easier to maintain), with a tight-fitting lid (they jump) and low-to-moderate flow; use gentle filtration and add broad-leaf plants, caves, and floating cover for security and resting near the surface.
- Maintain stable warm water at 25-28°C (77-82°F) with pH ~6.5-7.5 and low-to-moderate hardness; avoid rapid temperature swings and aim for 0 ammonia, 0 nitrite, and nitrate ideally <20 ppm with weekly water changes (typically 20-40% depending on stocking and nitrate).
- Feed a Betta-specific pellet as the staple (small portions 1-2x daily, only what's eaten in ~1 minute) and supplement several times per week with frozen/live foods like brine shrimp, daphnia, or bloodworms; fast one day weekly or reduce portions to prevent bloating/constipation.
- House males alone-never with another male Betta and avoid most other long-finned or similarly shaped fish (guppies, fancy tetras) that trigger aggression; suitable tank mates in larger planted tanks include peaceful snails and shrimp (may be hunted) and calm schooling fish like ember tetras or rasboras if the Betta is not overly aggressive.
- Provide access to the surface for air breathing (labyrinth organ) and avoid strong surface agitation; keep décor smooth and plants soft to reduce fin tears, especially for long-finned varieties.
- Watch for fin rot (ragged, receding fins), ich/white spots, velvet (gold dusting, flashing), swim bladder/bloating, and stress signs like clamped fins or lethargy; these are often linked to poor water quality, cold water, or overfeeding-test water promptly and correct conditions before medicating.
- If breeding, use a separate breeding setup with shallow warm water and lots of floating plants for bubble-nest building; condition the pair on high-protein foods, remove the female after spawning, and be prepared to separate fry/juveniles as males become territorial.
Compatibility
Good Tankmates
- Small, peaceful schooling fish (species-dependent) may work in larger, well-planted tanks; avoid known fin-nippers and monitor for chasing/stress
- Bottom-dwelling scavengers like Corydoras catfish (especially smaller species) that ignore the betta and occupy different space
- Kuhli loaches and other peaceful, shy bottom fish that hide often and don't compete at the surface
- Otocinclus (in suitably sized, established tanks) may work; use caution with plecos because some can harass/slime-coat rasp slow fish and require larger tanks
- Snails (nerite, mystery) as low-conflict invertebrates; provide cover if the betta investigates
- Non-nippy shrimp with caution (e.g., adult Amano shrimp); heavy planting/moss helps reduce harassment
Avoid
- Other male bettas (and often multiple females without a carefully managed setup): high risk of fighting, stress, and injury
- Fin-nipping or boisterous fish (e.g., tiger barbs, serpae tetras, some danios): likely to shred betta fins and cause chronic stress
- Long-finned, betta-like fish that may trigger aggression (e.g., guppies, fancy male endlers, some gouramis/angelfish)
- Large aggressive/semi-aggressive fish (e.g., most cichlids) that can bully, outcompete, or injure a betta
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