Freshwater care
Betta care: a reliable single-fish setup
Tank, heat, food and behaviour checks for Betta splendens.
Set up the home first
Betta splendens is a tropical fish, despite its reputation for surviving in cups. Start with a cycled aquarium of at least 5 gallons; more volume makes water chemistry more stable. Use a heater to keep the water around 78–82°F (26–28°C), a gentle filter, a lid and conditioned water. Add broad leaves or floating cover so the fish can rest close to the surface. Avoid décor with sharp edges that can snag long fins.
Plan for its temperament
One betta can be a complete display. Two males should not share a tank, and a mirror is not permanent enrichment. Tank mates depend on the individual betta, tank size and the other species: tiny fish may be chased, while fin-nippers can injure the betta. If you attempt a community setup, provide a larger tank with dense cover and have a separate home ready if aggression appears.
Feed and maintain
Use a quality betta pellet as the staple food, varied with suitable frozen or live foods. Offer a small amount that is eaten promptly rather than a large pinch that sinks and decays. Test ammonia and nitrite while the tank is new and whenever behaviour changes. Perform regular partial water changes with temperature-matched, conditioned water. Clean the filter gently; replacing all of its media can disrupt the nitrogen cycle.
Know when to act
Clamped fins, persistent hiding, frantic surface breathing, white spots or an inability to swim normally call for closer assessment. Check temperature and water quality first. One symptom alone does not identify a disease, so avoid guessing at treatment. An aquatic veterinarian or experienced fish-health professional is the right source for diagnosis when symptoms continue.
Source and further reading
Check the scientific name and local laws for any species you plan to buy, keep, catch or release. Care needs vary by species and circumstances.