Betta splendens: living card for the betta fish

Betta splendens (betta fish) attracts people through colour and behaviour, but its body asks for calm, warmth, and free access to the surface.

Quick read

• Type: tropical labyrinth fish from slow waters.
• Aquarium: mature, covered, with floating plants and very gentle flow.
• Indicative temperature: 25-28 C.
• pH: 6.5-7.5.
• Hardness: soft to moderate.
• Base volume: 20 L for a single male; more in a very calm community.
• Feeding: small carnivore, with quality pellets and fine frozen food.
• Difficulty: medium; easy to buy, easy to house badly.

What to check before buying

Look for intact fins, calm breathing, a normal belly, and a clear food response. Avoid apathetic fish kept cold in cups or with blackened fin edges.

Before buying, confirm that the aquarium is cycled, the group size or pair plan makes sense, and the setup runs at the species’ real temperature.

Aquarium design

The aquarium should reduce current and visual stress: secure lid, tall or floating plants, leaves, roots, and resting areas near the surface.

Use the card as a baseline, then watch the fish. Loss of colour, constant hiding, or all-day competition calls for a design correction before a chemical fix.

Working parameters

Stability matters more than chasing perfect pH. Keep the water clean, temperature constant, and avoid abrupt changes in salts or conditioners.

Treat these ranges as a working zone, not permission to swing parameters. Rapid changes, immature aquariums, and incompatible species cause most problems.

Compatibility and warning

It is not a fish for fin nippers, strong current, or rival males. In a community, choose only small, calm species that do not compete at the surface.

Clamped fins, rapid breathing, frequent jumping, or hiding all day indicate that the setup is failing.

Reference sources

FishBase for taxonomy and distribution; NOAA/University of Florida historical ornamental-trade data for frequent market species; Aquarium Co-Op and specialist aquarium guides for practical husbandry ranges.