Betta Fish Care: Tank, Heater and Diet

Quick answer

A betta needs a heated, filtered tank, not a bowl. Aim for at least 19 litres (5 US gallons), keep the water at about 24–27 °C (76–81 °F) with a thermostat heater, use a gentle filter and dechlorinated water, and feed a small amount of betta pellets once or twice a day. Keep only one male per tank.

Why bettas end up in cups

Bettas (Siamese fighting fish, Betta splendens) are often sold in small cups, and many people assume that's how they live. It isn't. In the wild they live in shallow, warm, heavily planted water, and they have a special breathing organ (the labyrinth organ) that lets them gulp air at the surface. That lets them survive in poor conditions. It doesn't mean they thrive in them.

A betta in a small unheated container is cold, sitting in its own waste and slowly getting sicker. Give it a proper setup and you get a far more active, colourful fish.

Tank size and setup

University of Illinois vets recommend a tank of 5 US gallons (about 19 litres) or larger. Bigger is easier, not harder: a larger volume of water holds its temperature better and waste builds up more slowly.

What to put in it:

• A lid. Bettas jump. Leave a small gap of air between the water and the lid so the fish can reach the surface to breathe.
• A gentle filter. Long fins are easily pushed around or sucked against a strong intake. A sponge filter or a filter with adjustable flow suits them best.
• Smooth decorations. Sharp plastic plants and rough ornaments tear fins. Silk or live plants are safer. Run a pair of tights over anything you're unsure about; if it snags, it can snag fins.
• Resting spots. Bettas like to rest near the surface. Broad leaves or a floating plant give them somewhere to perch.
• A cycled filter before the fish goes in. A new tank needs a few weeks to grow the bacteria that break down waste, so set it up and cycle it before you bring the fish home.

Heater and temperature

Bettas are tropical fish. Room temperature is usually too cold for them, and it rises and falls through the day and night, which stresses them. Vet and welfare sources give a target of roughly 24–27 °C (76–81 °F).

Use a submersible heater with a built-in thermostat and check it with a separate thermometer. The little lamps that come with some "betta bowls" are not a reliable heat source. Keep the tank away from windows, air conditioners and heaters so the temperature stays steady.

In very hot weather, the opposite problem appears. Warm water holds less oxygen, so watch the temperature in summer too, and keep the tank out of direct sun.

Water quality

Tap water needs a water conditioner (dechlorinator) to remove chlorine and chloramine. Don't use distilled water on its own, because it lacks the minerals fish need. A pH of around 7 suits most bettas; they generally cope with roughly 6.5 to 7.8, and a steady pH matters more than chasing an exact number.

A typical routine is to change 15–25% of the water each week, with conditioned water at the same temperature as the tank. Test ammonia, nitrite and nitrate regularly, especially in the first few months. Our guide to aquarium water changes explains how much to change and how often in more detail.

What to feed a betta

Bettas are carnivores. In the wild they eat insects and their larvae.

• Staple: a good-quality pellet or flake made for bettas.
• Treats: frozen or freeze-dried bloodworms or brine shrimp, a few times a week rather than every day.
• How much: only what the fish finishes in a few minutes, once or twice a day. A betta's stomach is tiny.

Overfeeding is the most common mistake. Uneaten food rots, fouls the water and can leave the fish bloated. If food is still drifting around after a few minutes, you're giving too much; scoop it out and feed less next time.

Tank mates

Never keep two males together. They're territorial and will fight, often to serious injury or death. Females can also be aggressive, and keeping a group of females needs a large, well-planted tank and some experience.

Some bettas tolerate calm, small companions in a bigger, well-filtered tank, such as snails, some shrimp or small peaceful fish like corydoras. Avoid fin-nippers (tiger barbs are the usual example) and other long-finned, brightly coloured fish that the betta may treat as a rival. Every betta has its own temperament, so watch closely for the first few days and have a backup plan.

Signs of a healthy betta, and warning signs

A healthy betta is alert, eats eagerly, swims around its tank and holds its fins open. Males often build bubble nests at the surface, which is normal.

Watch for:

• clamped fins, lethargy, lying on the bottom for long periods;
• refusing food for more than a day or two;
• ragged, shrinking or dark-edged fins, which can mean fin rot;
• white spots, cottony patches, swelling or raised scales;
• gasping at the surface rather than the usual quick gulp.

When any of these appear, test the water and check the temperature first. Poor water and cold water are behind a large share of betta health problems. If things don't improve after fixing the water, or the fish gets worse quickly, ask an aquatic vet or an experienced fish keeper for help.

Lifespan

With good care, bettas commonly live around 3 to 5 years. Fish bought as adults from a shop may already be a year or so old.

In Pakistan

Bettas are sold widely in aquarium shops and markets in Pakistani cities, often in small jars. Winter nights in the north and in places like Lahore and Islamabad drop well below what a betta needs, so a heater is a must for much of the year. In summer, tanks in hot rooms can climb past 30 °C (86 °F); keep them out of sun and check the temperature daily. Power cuts are common, so a battery-powered air pump and an insulated cover for the tank help during long outages. Prices vary a lot with fin type and colour, from cheap common veiltails to more expensive show-type halfmoons.

When you're ready to choose a fish, pick one that is active and has clean, intact fins; you can browse fish from verified sellers on Paalo.