Betta care: tank size, heat, and why not a bowl

Short answer: a betta is a tropical fish that needs a heated, filtered tank of at least 5 US gallons — not a bowl. In a proper tank you can hold a steady 78 to 80°F, run gentle filtration, and give the fish room to behave normally. A bowl has no heater, no filter and swings in temperature all day, which stresses the fish and shortens its life. Give a single betta 5 gallons or more, a small heater, a sponge or baffled filter, and a varied diet, and it will be a far healthier, more active pet.

Why not a bowl

Bettas come from warm, still waters in Southeast Asia. They breathe air from the surface using a labyrinth organ, which is why people assume they can live in tiny unheated containers. They cannot — at least not well. Room temperature in most Alberta homes sits well below what a betta needs, and an unheated bowl also cools further overnight. Cold, unstable water suppresses the immune system and invites disease.

A bowl also has no biological filtration, so ammonia from waste builds up quickly in a small volume. That is the single most common reason pet-store bettas fade. A cycled, filtered tank keeps that ammonia in check.

Tank size and setup

5 US gallons is a sensible minimum for one betta; more is better and easier to keep stable. A larger footprint gives you room for plants, a gentle current and a bit of behaviour. Cover the tank — bettas jump.

• Heater. Use a small pre-set or adjustable heater sized to the tank and aim for 78 to 80°F. A Fluval nano heater suits tanks in this range. For sizing across other volumes, see our heater sizing guide.
• Filter. Bettas dislike strong flow, which tears at their long fins. A gentle sponge filter such as the Aquatop internal sponge filter is ideal, or baffle a small hang-on-back. Our filter guide compares the options.
• Cycle first. A betta tank still needs a nitrogen cycle like any other. Set it up ahead of time rather than adding the fish to brand-new water.

Feeding

Bettas are carnivores and do best on a betta-specific pellet as a staple, with the occasional frozen or freeze-dried treat like bloodworms or brine shrimp for variety. Feed a small amount once or twice a day, only what the fish clears in a minute or two, and skip a day now and then. Overfeeding fouls the water and causes bloating. Browse betta pellets and treats in our fish nutrition range.

Tankmates and temperament

Male bettas will fight other males and often flare at anything with long fins or bright colour, so never keep two males together. In a larger, well-planted tank of 10 gallons or more, a single betta can sometimes share space with calm, non-nippy tankmates such as snails or small bottom fish, but temperament varies from fish to fish. If in doubt, keep the betta on its own — it will be perfectly content. We are happy to talk through combinations for your specific tank.

Browse and ask

You can see our current bettas in the betta collection, and the small heaters and gear to set one up properly. If you have questions about your particular setup, please ask.

Written by the team at Tropical Fish Imports in Lethbridge, Alberta. Last reviewed August 2026.

Not sure what size tank or heater suits your space? Tell us what you have in mind and we will help you get it right — visit the shop, call 403-380-4506, or send us an email.