Betta fish

Overview

The betta, or Siamese fighting fish, may be the best-known aquarium fish in the world. Wild bettas come from rice paddies, ponds and slow canals in Thailand and Southeast Asia, while the domestic betta is the result of centuries of selective breeding: today's males come in huge-finned forms (veiltail, halfmoon, crowntail, short-finned plakat) and every color imaginable.

As a labyrinth fish it can breathe air at the surface, which fed the myth that bettas are happy in a cup or a tiny vase. They are not: bettas are tropical fish that need warm, filtered, stable water. They are curious, recognize their keeper and have real personality, making them a great pick for a first small tank that is set up properly.

Care and tank setup

A male needs at least 5 gallons (20 L), and 10 gallons (38 L) is even better, in a cycled tank with a heater and a gentle filter. Unheated, unfiltered bowls and "betta cubes" lead to disease and a short life, no matter how they are marketed.

• Steady 77-81 °F (25-27 °C) and weekly water changes.
• Lots of plants, especially floaters and broad leaves to rest on near the surface.
• A lid: bettas jump, and warm air above the water is good for them.
• No sharp decor that can tear long fins.

Never keep two males together; they fight until badly injured, and females can be aggressive too. In a community tank of 15-20 gallons or more, a betta can live with small, calm fish that do not nip fins (corydoras, rasboras, otos), but avoid barbs, serpae tetras, fancy long-tailed guppies or other flashy fish it may treat as rivals. Many bettas hunt shrimp.

Feeding

Bettas are carnivores that naturally eat insects. Feed a quality betta pellet and add frozen or live foods such as bloodworms, brine shrimp or daphnia. Give one or two small meals a day, only what it eats in a couple of minutes. Overfeeding is the most common cause of constipation, bloating and dirty water, and one fasting day a week is healthy.

Breeding

The male builds a bubble nest under a floating leaf, wraps around the female beneath it and catches the falling eggs to place them in the nest, which he guards alone. The female should be removed after spawning. Breeding bettas is doable but takes planning: a separate tank, infusoria for the tiny fry and, later, dozens of jars or containers to separate young males.

Compatible tank mates

Species from our database that share water parameters, size and temperament with the Betta fish. Calculated from the data in each profile.

Check the compatibility of your whole tank →

What not to keep it with

Popular species you shouldn’t house with the Betta fish, and why.

• Tiger barb: nips long fins
• Clown loach: one may eat the other due to size
• Oscar: one may eat the other due to size, incompatible temperaments
• Ember tetra: one may eat the other due to size
• Amano shrimp: eats shrimp
• Cherry shrimp: eats shrimp

Recommended equipment

What you need to keep the Betta fish healthy, checked against Amazon stock.