Freshwater Fish · Bettas

Long-finned Betta

Betta splendens

Flowing-finned labyrinth fish that lives aloneBeginner

Lifespan: 3-5 years
Size: 2.5 in
Social needs: Solitary (males); kept without tankmates
Time: 10-15 min daily; weekly water change
Cost: Low
Diet: Carnivore (high-protein pellets, frozen foods)

Overview

What is this animal?

Bettas are labyrinth fish from the slow, warm waters of Southeast Asia, able to gulp air from the surface.
Selective breeding, mostly in the last hundred years, produced the long finnage and bright colours sold today, but the fish beneath is hardy and learns to recognise its keeper.

This guide covers the long-finned forms most shops sell, such as the veiltail, halfmoon, crowntail and double tail; the short-finned plakat is the same species and has its own guide.

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Despite their reputation as desk ornaments, bettas do well only in a heated, filtered, cycled tank.
Their tolerance of poor water is a survival trait, not a reason to skip proper care.
Given a stable setup they are interactive and long-lived.

Temperament

Males are territorial and must be housed alone, as two males will fight and even a mirror can stress them.
The name Siamese fighting fish reflects this instinct.

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They do not need company and are content as the sole occupant.

They become curious and bold once settled, flaring, following fingers, and learning feeding routines.
Females can sometimes share a heavily planted larger tank as a sorority, but this is advanced and not recommended for beginners.

A good fit for

First-time keepers wanting an interactive fish
A heated 24 in tank on a sturdy stand
People who like a single characterful pet
Keepers who can commit to weekly water changes

Common mistakes to avoid

Housing in unheated bowls or vases
Keeping two males together
Overfeeding causing bloat and swim-bladder issues
Assuming they tolerate uncycled water long-term
Strong flow or sharp decor that tears long fins

Enclosure

Minimum 15 gallons

Must be housed alone. Solitary (males); kept without tankmates

Provide at least 15 US gallons in a tank at least 24 in long, such as a standard 15-gallon, with a gentle filter and a reliable heater holding 77-82°F.
A tight lid is essential, as bettas jump and need an undisturbed warm air layer to breathe.
Silk or live plants and a cave give security and resting spots near the surface.

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Keep flow low, since long fins tire in strong currents.
Cycle the tank before adding the fish and aim for ammonia and nitrite at zero and nitrate under 20ppm.
Bowls, vases, and unheated nano cubes are inadequate and shorten lifespan, and the 5 gallons often quoted is a floor rather than a good home.

Check your enclosure

Supplies

Setup

Tank and stand
Filter
Heater and thermometer
Substrate, plants and decor
Liquid test kit
Dechlorinator and starter supplies

Ongoing

Quality betta pellets (fish or shrimp meal listed first)
Frozen bloodworm blister pack
Frozen daphnia
Frozen brine shrimp
Feeding tweezers or a pipette

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Small thawing cup
Fine net for removing uneaten food

Safe substrate: Fine, smooth sand · Smooth, rounded fine gravel (not for loaches or sand-sifting cichlids; sand is better for corydoras) · Bare bottom (quarantine and grow-out only)

Work out the cost

Care routine

Daily

Check temperature and equipment
Feed a few pellets
Head-count and look everyone over

Every few days

Check the finsevery 3 days
Top up evaporationevery 3 days

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Weekly

Check the lid and air gap
Test the water
Water change and gravel vacuum
Wipe the front glass only

Every few weeks

Trim and thin the plantsevery 2 weeks

Monthly

Check supplies and reagent dates
Replace or recharge chemical media, if you use any (skip it in a blackwater tank)
Rinse the filter media

Health review: Quarterly tank and fin review, every 3 months

Tools

Is your enclosure big enough?Check your measurements against the recommended size What will it cost?Setup, monthly and over its whole life, itemised Is this ammonia reading dangerous?Works out the toxic part from your pH and temperature

Care in depth

Diet

Carnivore (high-protein pellets, frozen foods)

Bettas are carnivores and need a meat-based diet.
Feed a quality betta-specific pellet as the staple, supplemented several times weekly with frozen or live bloodworms, daphnia, and brine shrimp.
Variety supports colour, finnage, and digestion.

Feed only what is eaten in two minutes, once or twice daily, and include a weekly fasting day to reduce constipation and bloating.
Overfeeding is a leading cause of swim-bladder problems and fouled water in betta tanks.

Health

Signs of good health, and the common problems

Common ailments are fin rot, fungal infections, and swim-bladder disorder, most traceable to cold water, poor filtration, or overfeeding.
Stable warmth and clean parameters prevent most disease.
Watch for clamped fins, lethargy, and loss of appetite as early warning signs.

Long-finned and double-tail forms can suffer fin-weighting and spinal issues, and some long-finned males bite their own tails, which usually points to stress, so look at the tank before blaming the fish.
Quarantine new plants and decor, avoid sharp ornaments that tear fins, and treat illness promptly with the correct medication rather than salt alone.

Is this urgent?

6 warning signs and how fast to act, 3 of them right away

In a fish tank the patient is usually the water. Test before you treat: dosing a healthy tank for a disease it does not have makes things worse.

Go now

Any detectable ammonia or nitrite in a stocked tankLarge water change now with dechlorinated, temperature-matched water. Stop feeding. Test again in 12 hours. Both are directly toxic. How toxic the ammonia reading is depends on pH and temperature, so the same number can be harmless or lethal.

Now

Fish gasping at the surface with fast gill movement, or crowding the filter outflowIncrease surface movement now (gently in a betta or gourami tank, without creating a strong current), then test the water. Either the oxygen has crashed or the gills are being chemically burned. Both are hours-scale problems. Bettas, gouramis and corydoras rise to gulp air as part of normal breathing; the warning is constant gulping, fast gill movement, or the whole group hanging at the top.

Now

Sudden deaths, more than one fish in a dayTest ammonia, nitrite, nitrate and temperature before doing anything else. Do not add medication yet. Multiple simultaneous deaths usually point at the water or the equipment rather than a pathogen, so rule those out first.

Now

Today

Flashing: repeatedly scraping against decor or substrateTest the water, then look closely for parasites. Irritation is either chemical or parasitic; the test tells you which before you medicate.

Today

White salt-grain spots over the body and finsBegin the appropriate treatment today and check the temperature. The parasite's life cycle is temperature-driven, and it multiplies with every cycle you wait.

Today

Soon

Clamped fins, hiding, or refusing food for more than two daysTest the water and review recent changes. Usually the earliest visible sign of a parameter drifting.

A few days

Never add a new fish to a tank that is not fully cycled, and never treat blind. A test kit is cheaper than the fish.

This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it, and the time to find one is before you need one.

Bedding and substrate

3 safe, 4 with a caveat, 2 to avoid

Substrate in an aquarium is a filter as much as a floor. Most of the biology lives in and on it.

Safe

Fine, smooth sandCorrect for corydoras, kuhli loaches, eartheaters such as rams and acaras, and anything else that sifts or burrows. Barbels wear away on sharp gravel.

safe

Smooth, rounded fine gravel (not for loaches or sand-sifting cichlids; sand is better for corydoras)Rinse thoroughly before use. Grain size should be too large to swallow and too small to trap food. Kuhli loaches need sand to burrow into and rams and acaras sift mouthfuls of it; bronze and panda corydoras manage on smooth fine gravel, but sterbai corydoras need sand.

safe

Bare bottom (quarantine and grow-out only)Legitimate for quarantine and grow-out tanks. Easy to clean, but it holds far less biological filtration, and it is no long-term home for burrowing loaches or sand-sifters.

safe

With a caveat

Crushed coral or aragoniteDeliberately raises hardness and pH. Correct for rift-lake cichlids, wrong for soft-water species.

with a caveat

Aquasoil for planted tanksExcellent for plants, but most active soils soften the water and pull pH and KH down for months, and many leach ammonia for the first weeks. Right for soft-water species; wrong for hard-water animals (livebearers, rainbowfish, goldfish, and snails, whose shells erode in soft, acidic water) unless you test GH and KH and remineralise. Cycle around it; do not stock into it.

with a caveat

Very deep sand bedsAnaerobic pockets form below about 2 inches in still sand. Either keep it shallow or keep it stirred.

with a caveat

Painted or coated gravelUsually fine, but coatings chip. Test a handful in a jar for a week first.

with a caveat

Never

Sharp or angular gravel with bottom-dwellersWears down barbels and leads to infection in corydoras and loaches.

never

Anything containing metal, limestone of unknown origin, or shells in a soft-water tankSlowly alters chemistry in ways that are hard to diagnose later.

never

This is our general list for freshwater fish. We have not built one specific to Bettas yet.

Top resources for more info

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