Short direct answers to the most common betta questions. For depth on any topic, follow the linked spokes (PMC9334006).
The four essentials
- 5-gallon minimum tank. tank setup.
- Heater to 25-27 °C. best heaters.
- Filter (sponge works). the nitrogen cycle.
- Varied diet, one fast day per week. betta feeding.
Everything else is downstream of those four.
Common topics
Care basics: the care guide. Pillar page with every care decision.
Disease diagnosis: the disease guide. Pillar page with the differential table.
Breeding project: the breeding guide. 5-month commitment.
Genetics: the genetics guide. Color and fin inheritance.
Wild species: the wild species guide. 70+ species beyond the pet-trade betta.
Buyer’s guides: best 5-gallon tanks, best heaters, best pellets, best plants.
The three biggest mistakes
- Undersized tank. The pet-store bowl is the single most common cause of premature betta death.
- No heater. Cold tanks produce fin rot and immune suppression.
- Overfeeding. Obesity, swim bladder issues, fatty liver disease.
Avoid all three and your fish reaches year 3 confidently.
When in doubt
- Test water first. Most “mystery illness” is an ammonia or temperature issue.
- Read the disease spokes before medicating.
- Never dose Melafix, Bettafix, or tea tree oil products on bettas.
- Quarantine every new fish for 2 weeks.
- Start with the the care guide pillar if you’re overwhelmed.
When a claim here conflicts with what you’ve read elsewhere, follow the primary source cited in the spoke and work from that.
Related on this site
- Betta Fish Care: The Evidence-Based Guide
- Betta Disease: Diagnosis and Treatment, Evidence-Based
- How to Breed Betta Fish: A Breeder’s Complete Guide
- Pet-Store Betta Ethics: What the Cup Costs the Fish
- Betta Resources: Primary Sources, Organizations, and Further Reading
Frequently asked
- What's the minimum tank size?
- 5 US gallons (19 L). Anything smaller produces chronic ammonia stress.
- Do bettas need a heater?
- Yes. Stable 25 to 27 Celsius. Cold bettas stop eating and develop fin rot.
- Do bettas need a filter?
- Yes. Sponge filter at gentle flow is the standard.
- How long do bettas live?
- 2 to 4 years in good conditions. Outliers past 5.
- How often do I feed?
- Once daily, 4 to 6 small pellets. One fast day weekly.
- Can bettas live with other fish?
- Yes with care. 10+ gallons, no fin-nippers, no other male bettas. See /care/tank-mates/.
- Why is my betta not eating?
- Check temperature first. Cold is the most common cause. Check food freshness next.
- Why is my betta resting on the bottom?
- Could be normal rest or illness. Check water parameters. If ammonia or nitrite above zero, water change immediately.
- How often do I change water?
- 25 to 30 percent weekly in a cycled 5-gallon. More often in smaller or uncycled setups.
- Can I keep two male bettas?
- Never. They fight to exhaustion or death.
- Are sororities hard?
- Yes. Most fail. Not recommended for beginners.
- Do bettas jump?
- Yes. Always use a lid.
- Do I need live plants?
- No but they help. Anubias and Java fern are the default choices.
- Is the peace-lily vase OK?
- No. It's animal cruelty. See /care/betta-vase-myth/.
- What's the safest medication to have on hand?
- Seachem Kanaplex for bacterial infections and Hikari Ich-X for parasites. See /disease/.
- Is Melafix safe?
- No. Tea tree oil irritates the labyrinth organ. Don't use on bettas.
- Why is my betta's color changing?
- Marble pattern is unstable throughout life. Non-marble color can deepen with age or dull with illness. Check parameters.
- Can bettas breathe air?
- Yes. They have a labyrinth organ. They need surface access.
- Why does my betta flare at his reflection?
- Territorial response. A mirror for 60 seconds a day is fine. Constant reflection is chronic stress.
- Where should I buy a betta?
- For pet: reputable local fish store. For show or breeding: named breeders through AquaBid or IBC directory. See /buyers-guide/where-to-buy-show-bettas/.