Choosing and Buying a Healthy Betta, Plus Quarantine

Betta Gillfriend care rules: one betta per tank. Mirror or flare practice: one 2-minute session a day, with at least 2 rest days a week. Train: up to 10 minutes a week.

The best way to avoid disease is to start with a healthy fish and keep anything new away from your other fish until you're sure it's healthy. That's what this section is about.

Before you buy

Your tank is set up and cycled (ammonia and nitrite at 0). See Tank setup.
The heater holds a steady 76–81°F (24–27°C).
You have a test kit, water conditioner and a lid.
Ideally, you have a quarantine tank ready, especially if you already have other fish.
You know where your nearest aquatic vet is (fishvets.org).
You're ready to care for this fish for its whole life (often 3–5 years).

Where to buy

Source	Things to consider
Local fish store	You can see the fish first. Look at the store's overall standards: clean tanks, dead fish removed promptly, knowledgeable staff. OATA advises not buying even a healthy-looking fish if sick fish are in the same tank.
Specialist or local breeder	Often healthier, well-fed fish with known age and history. You can ask questions about parents, diet and any treatments.
Online breeders and importers	Huge variety (including giants and show types), but the fish is shipped, often internationally, which is stressful. Choose sellers with good reviews and clear guarantees, and quarantine carefully. A UF/IFAS fact sheet notes that well over 100,000 male bettas are shipped from Thailand each week.
Rehoming / rescue	A lovely option. Ask about the fish's history and quarantine anyway.

Signs of a healthy betta

RSPCA Australia and OATA describe what to look for:

✅ Look for	❌ Avoid
Bright, even colour	Very pale, dull or patchy colour; long-lasting stress stripes
Fins held open (or neatly, for plakats), with clean edges	Clamped fins; ragged, melting or discoloured edges
Alert and responsive; follows your finger	Lethargic; lying on the bottom; hiding constantly
Swims level and with control	Sinking, bobbing, floating, listing or swimming in spirals
Steady, calm breathing	Fast breathing; gasping; one gill cover flared
Clear, bright eyes	Cloudy or bulging eyes
Smooth body, scales lying flat	Lumps, ulcers, white spots, gold dust, fuzz or film; scales sticking out
Healthy belly	Sunken or swollen belly
Clean vent	Trailing, stringy or white faeces; anything poking out of the vent
Interested in food (ask the store to feed it)	Ignores or spits out food

Tip: Cups at shops are temporary housing, and fish in them can look stressed or pale. Look past the cup and focus on fins, eyes, breathing, body and alertness.

Choosing for type and personality

Plakats (short fins, like Rip) are hardier swimmers and less prone to fin tears and fin biting.
Long-finned types (halfmoon, rosetail, veiltail) need especially gentle flow, soft decor, and resting spots.
Giants need a larger tank (we recommend 10+ gallons) and more food.
Young fish are smaller and less colourful but may live longer with you. Ask about age if you can.

See Betta types for each type's care notes.

Bringing your betta home

Take your betta straight home. Keep the bag or cup dark and warm (out of sun and cold), and avoid knocks.
Follow the steps in Acclimation. Don't pour the store water into your tank.
Shipped fish: open the box in a dim room. Fish may be pale and stressed. Acclimate gently, and give them peace and darkness for the first day.

Quarantine

Why quarantine?

Many dangerous betta diseases, including gill flukes, velvet, ich and columnaris, arrive with new fish (or plants, or water) that look perfectly healthy. UF/IFAS explains that fish with some immunity can carry gill flukes without showing signs, and that stress from shipping often triggers ich 1–3 weeks after arrival. Quarantine gives hidden problems time to show, in a tank where they can be treated without risking your other fish.

Warning: Merck notes that quarantine can't detect every disease. Mycobacterium, for example, can't currently be detected in live fish. But it is most useful for catching external parasites, which are some of the most common killers. Quarantine is still one of the most powerful things you can do.

How long?

At least 4 weeks. UF/IFAS recommends at least four weeks to catch gill flukes and other parasites; Merck uses a minimum of 30 days for some fish. Betta Gillfriend recommends 4–6 weeks. Restart the clock if any fish in quarantine gets sick.

Who should be quarantined?

Every new fish, including bettas, tank mates, and fish from trusted sources.
Snails and shrimp can carry disease-carrying water and hitchhikers. Quarantine them too.
Plants from tanks with fish: quarantine them in a separate fish-free container for a few weeks, or choose plants grown without fish (such as tissue-culture plants).
Even a single betta going into its own new tank benefits from the "watch closely" part of quarantine, even if there's no other fish to protect.

The quarantine tank

Merck describes an inexpensive setup: a 10-gallon tank, sponge filter, small air pump and heater. See Setting up a hospital tank for the full list.

Pre-seed the sponge filter by running it in your healthy main tank for a few weeks before you buy (Merck), so the quarantine tank is cycled from day one.
Keep it simple, with no substrate and just a hide or two, so you can see the fish and clean easily.
Give it its own nets, siphon and bucket (Merck), and wash your hands between tanks.
Same temperature as your main tank, 76–81°F (24–27°C).

What to watch during quarantine

Use the app's daily health check. Watch especially for:

Breathing: speed, effort, and whether both gill covers move evenly (gill flukes)
Flashing or rubbing
Spots, dust, fuzz or film (use a torch from the side for velvet)
Fin edges
Appetite and faeces
Swimming and buoyancy

Should I treat preventively?

Merck says preventive treatment during quarantine can be sensible for some groups of fish, including praziquantel for gill and skin flukes. UF/IFAS recommends taking steps to prevent fluke introduction with new fish, even when the new fish appear healthy.
But blindly treating every new fish with several medicines can stress it and cause harm. The best approach is to ask an aquatic vet. Many will advise a gill/skin check (a quick biopsy) during quarantine, and whether a preventive fluke treatment is worthwhile for your situation.

After quarantine

If your betta has been healthy for the whole quarantine period, move them to the main tank (acclimating as usual).
Disinfect the quarantine tank and equipment, rinse thoroughly, and store dry until next time (Merck).

Sources

Care guide by Betta Gillfriend (Bespok Labs, BC, Canada). It is general information, not vet advice. If your betta is sick, ask an aquatic vet.