Betta fish care guide
Also called: Betta, Siamese fighting fish, Fighting fish, Plakat, Halfmoon betta, Crowntail betta, Veiltail betta
The betta is a colorful, long-finned labyrinth fish that breathes air at the surface and is usually kept alone. Give it a heated, filtered tank of at least 5 gallons (19 L), ideally 10 (38 L), with gentle flow and never another male betta.
Bettas need a tank of at least 5 gallons (19 L), and water at 24–28°C (75–82°F) with a pH of 6–8. They grow to about 6.5 cm (2.6 in) and are semi-aggressive.
Plan a tank with bettasSee all tank mates
Betta fish quick facts
| Scientific name | Betta splendens |
|---|---|
| Family | Osphronemidae |
| Origin | Central Thailand and the Mekong basin, Southeast Asia (pet-store fish are captive-bred long-finned strains) |
| Adult size | 6.5 cm (2.6 in) |
| Minimum tank | 5 gallons (19 L) |
| Temperature | 24–28°C (75–82°F) |
| pH | 6–8 |
| Hardness (GH) | 2–15 dGH |
| Group size | Alone (only one male) |
| Temperament | Semi-aggressive; males fight each other |
| Swims at | Top |
| Diet | Carnivore |
| Care level | Easy |
| Lifespan | 2–5 years |
| Safe with shrimp? | No, eats shrimp |
| Safe with plants? | Yes |
- Known jumper: keep a tight-fitting lid.
- Long fins attract fin nippers.
Tank setup
Give one betta at least 5 gallons (19 L) with a heater, a gentle filter and a lid. A 10-gallon (38 L) tank or larger is easier to keep stable and is the minimum if you want tankmates. Add live or silk plants and leave a small air gap under the lid, since it gulps air at the surface. Avoid bowls and jars.
How many bettas in a tank?
The smallest common tank that suits bettas is a 5 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Bettas (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Up to 2 |
| 10 gallon | Up to 5 |
| 15 gallon | Up to 8 |
| 20 gallon | Up to 10 |
| 20 gallon long | Up to 10 |
| 29 gallon | Up to 15 |
| 40 gallon | Up to 21 |
| 55 gallon | Up to 30 |
| 75 gallon | Up to 41 |
| 125 gallon | Up to 68 |
Numbers are bioload limits only. Males fight, so keep one male unless the tank is large and well planned.
What you need for bettas
Sized for a 5 gallon tank, the smallest common size that suits bettas. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 5 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Adjustable heater, 25 W (opens Amazon in a new tab)Holds about 79 °F (26 °C) in a room at 68 °F (20 °C). A bigger heater can overheat a small tank if it sticks on. How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Sponge filter for 10 gallons (opens Amazon in a new tab)Gentle flow, about 10–20 GPH, suits bettas, which prefer slow water. Needs a small air pump. How to choose
- About 15 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 16 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for bettas
- Betta pellets (opens Amazon in a new tab)Feed a few pellets once or twice a day; bettas overeat.
- Indian almond leaves (opens Amazon in a new tab)Release tannins that soft-water fish like bettas and rams enjoy.
- Tight-fitting lid for a 5 gallon tank (opens Amazon in a new tab)Betta fish can jump out of an open tank.
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Water parameters
Keep it at 24–28°C (75–82°F), pH 6.0–8.0 and soft to moderately hard water. It needs a heater in almost every home, because a cool room makes it sluggish and prone to disease. Use dechlorinator, and change about 30% of the water every one to two weeks in a filtered 10-gallon tank.
Best tank mates for bettas
These popular species share bettas' water needs and temperament. See the full list of 50 good matches.
Nerite snail
2.5 cm (1 in) · 22–27°C (72–81°F)
Bristlenose pleco
12 cm (4.7 in) · 22–26°C (72–79°F)
Bronze corydoras
7 cm (2.8 in) · 21–26°C (70–79°F)
Assassin snail
2.5 cm (1 in) · 22–27°C (72–81°F)
Ramshorn snail
2 cm (0.8 in) · 21–27°C (70–81°F)
African dwarf frog
3.5 cm (1.4 in) · 22–26°C (72–79°F)
Malaysian trumpet snail
2.5 cm (1 in) · 20–27°C (68–81°F)
Mystery snail
5 cm (2 in) · 21–26°C (70–79°F)
Avoid keeping bettas with
- Angelfish: Betta fish tends to attack colourful, long-finned fish like angelfish, mistaking them for rivals.
- Cherry shrimp: Betta fish eats small shrimp like cherry shrimp.
- Common goldfish: They need different temperatures: Betta fish 24–28°C (75–82°F), common goldfish 15–22°C (59–72°F).
- Dwarf gourami: Betta fish tends to attack colourful, long-finned fish like dwarf gouramis, mistaking them for rivals.
- Fancy goldfish: They need different temperatures: Betta fish 24–28°C (75–82°F), fancy goldfish 18–23°C (64–73°F).
- Guppy: Betta fish tends to attack colourful, long-finned fish like guppies, mistaking them for rivals.
Feeding
Bettas are meat eaters that feed on insects and larvae in the wild. Use a quality betta pellet as the staple, plus frozen or freeze-dried bloodworms, daphnia or brine shrimp a few times a week. Feed once a day, only what it eats in about a minute, as bettas get fat and bloated easily.
Behavior
Males fight each other and can badly injure or kill one another, so keep only one male per tank. Males also attack fish with long, bright fins, like fancy guppies, and other gouramis may be treated as rivals. Ember tetras, pygmy corydoras and snails often work in 10 gallons (38 L), and kuhli loaches or regular corydoras in about 20 gallons (76 L), but each betta has its own temper. Fin nippers such as tiger barbs will shred its fins.
Breeding
The male builds a bubble nest at the surface and guards the eggs and young. Breeders use a small 5–8 gallon (20–30 L) tank with plenty of cover for the female and a tight lid to keep the air humid. Eggs hatch in 1–2 days, and fry need infusoria first, then baby brine shrimp or microworms.
Tips from experienced keepers
- Use a heater. In a cool room, bettas turn sluggish and get sick more easily.
- Pick a gentle sponge filter or a filter with low flow. Strong current tires out long-finned bettas.
- Never mix two males. Female groups are possible but often fight.
- Keep a tight lid and leave an air gap. Bettas jump and need to gulp air.
- Watch any tankmates closely for the first weeks, and have a backup plan.
Frequently asked questions
What size tank does a betta fish need?
At least 5 gallons (19 L) with a heater and filter. A 10-gallon (38 L) tank is better and is the minimum if you want to add tankmates.
Can betta fish live with other fish?
Often yes, in a planted tank of 10 gallons (38 L) or more. Ember tetras and pygmy corydoras suit 10 gallons, while kuhli loaches and larger corydoras need about 20 gallons (76 L). Avoid fin nippers, other bettas, gouramis and fancy guppies.
Can bettas live with shrimp?
Bettas are known for hunting shrimp, so cherry shrimp are often eaten. Larger amano shrimp have a better chance, especially in a densely planted tank with moss and wood to hide in.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.