Betta Fish Set-Up: Tank, Heater, Food and Care Basics

Betta fish (Siamese fighting fish) are beautiful, curious and full of personality. They're also tropical fish with real needs — and the tiny cups they're sold in are not a home.

1. A tank of 5 gallons or more

A 5-gallon tank is a common minimum for one betta. More water stays cleaner and more stable, and gives your betta room to explore. A complete kit with a built-in filter and light is the easiest start.

2. A heater — bettas are tropical

Bettas come from warm water and do best at around 76–82°F (24–28°C). Most homes are cooler than that, so a small adjustable heater is essential, along with a thermometer to check it. Choose a low wattage for small tanks — the EHEIM Jager comes in a 25 W size.

3. Gentle filtration

Bettas have long fins and don't like strong currents. Turn the filter outflow down, or soften it with a sponge, so your betta can swim without being pushed around.

4. Treat the water and cycle the tank

Every time you add tap water, use a conditioner. Before your betta moves in, let the tank run for a few weeks to grow beneficial bacteria (see our first aquarium guide).

5. Light and a lid

A timed light keeps a steady day-night rhythm. Bettas can jump, so keep a lid on.

6. Feed small amounts

A betta's stomach is tiny. Feed a few pellets once or twice a day, and skip one day a week. Overfeeding is the most common cause of cloudy water and bloating.

7. Keep males alone

Male bettas will fight other males and often harass other fish. Keep one male per tank unless you're experienced with community set-ups.

The checklist