The Complete Guide to Breeding Betta Fish

Before you start

Breeding bettas is rewarding, but it takes commitment. From pairing the breeders until the young are ready to be separated takes about 2–3 months, with feeding several times a day and regular water changes. One spawn can produce hundreds of fry, so also plan how you will raise, select, and rehome them.

• Time: daily checks for 2–3 months, especially during the first two weeks after the eggs hatch.
• Space: a spawning tank, a larger grow-out container, and dozens of jars or bottles to separate the males.
• Live food: an infusoria culture and brine shrimp eggs must be ready before the pair is introduced.
• A goal: decide which variety and traits you want to keep, such as Halfmoon fins or Koi coloring, so you choose the breeders with purpose.

Choosing the breeding pair

The breeders largely decide the quality of the young. Choose a male and a female that are healthy, mature, and right for your breeding goal.

• Ideal age 5–8 months (range 4–12 months). Breeders that are too young are not yet settled, while older ones tend to produce fewer eggs.
• Healthy and active: bright color, intact fins, a good appetite, and no white spots, fungus, bloating, or raised scales.
• A ready male builds bubble nests often and flares his fins.
• A ready female has a round belly full of eggs, a visible white spot (the ovipositor) between the ventral and anal fins, and vertical bars on her body when she is ready to spawn.
• Pair the same variety and fin type, such as Halfmoon with Halfmoon or Plakat with Plakat, for more consistent results.
• Avoid breeding siblings again and again without new bloodlines, because the risk of deformities and weaker fish increases.

Equipment and water quality

• A 20–40 liter spawning tank (for example 40 × 25 × 25 cm) filled with 10–15 cm of water. Shallow water helps the male collect the eggs and helps the fry reach the surface.
• A lid to keep the air above the water warm and humid. This matters for the development of the fry's labyrinth organ.
• A heater and a thermometer to keep the temperature stable at 26–28 °C.
• No strong current. Switch the filter off or use a sponge filter with very small bubbles, because hang-on filters can suck in eggs and fry.
• Hiding places for the female, such as aquatic plants (moss, salvinia, or hornwort), Indian almond leaves, or pieces of pipe.
• A nest anchor, such as an Indian almond leaf or half a floating foam cup, where the male builds his bubble nest.
• A glass divider or a clear container to introduce the pair without direct contact.
• A 60–100 liter or larger grow-out container, plus jars or bottles to separate the males later.

Use chlorine-free water, either aged for 24–48 hours or treated with a dechlorinator. Aim for pH 6.5–7.5 with low to moderate hardness. Indian almond leaves release tannins that lower the pH slightly and help prevent fungus.

Conditioning the breeders (1–2 weeks)

Conditioning brings the breeders into their best shape before they meet.

• Keep the male and the female in separate containers where they can see each other.
• Feed small portions of high-protein food 2–3 times a day: bloodworms, mosquito larvae, water fleas (Daphnia or Moina), brine shrimp, and quality pellets.
• Change the water regularly so leftover food does not spoil it.
• Watch for readiness: the female grows rounder with a clear ovipositor, and the male starts building a bubble nest.

Setting up the spawning tank

1. Clean the tank without soap, then fill it with 10–15 cm of chlorine-free water.
2. Set the temperature to 27–28 °C and let it settle for 1–2 days.
3. Add an Indian almond leaf, plants to hide in, and a nest anchor.
4. Put the male in first so he claims the territory and starts a bubble nest, usually within 1–2 days.

Introducing the pair

1. Place the female in a clear container or behind a divider inside the spawning tank for 1–3 days so they can see each other.
2. Watch for readiness: the male flares, enlarges the nest, and guides the female; the female shows vertical bars, lowers her head, and approaches the nest.
3. Release the female when both are ready, ideally in the morning or evening when it is calm.
4. Chasing and a few torn fins are normal. Remove the female if she is badly hurt or if there is no spawning after 2–3 days, then condition the pair again for 1–2 weeks.

The spawning

The male leads the female under the nest and wraps his body around her (the embrace). The female releases eggs that are fertilized at once, and the male picks up the falling eggs and spits them into the nest. The embraces repeat for 1–3 hours and usually produce 100–500 eggs.

• Do not tap, move, or shine bright lights on the tank while it happens.
• The female sometimes stays still for a moment after an embrace; this is normal.
• If the female eats the eggs, remove her right away.

After spawning: caring for the eggs

1. Remove the female as soon as spawning ends, when she moves away from the nest and the male starts chasing her off.
2. Care for the female in clean water with an Indian almond leaf and nutritious food, and let her rest for 3–4 weeks before spawning her again.
3. Let the male guard the nest. Do not feed him, or feed him very little, for 2–3 days to keep the water clean.
4. The eggs hatch in 24–48 hours at 27–28 °C. White, fuzzy eggs were not fertilized, and the male usually removes them.
5. For 2–3 days the fry hang from the nest while they absorb their yolk, and the male puts back any fry that fall.

Free-swimming fry

About 2–3 days after hatching, the fry start swimming horizontally. This is the moment to start feeding and to remove the male.

1. Remove the male 3–5 days after the eggs hatch, when most fry swim freely, so he does not eat them.
2. Keep the lid on and the temperature stable.
3. Start feeding micro food on the day the fry swim freely.

Staged feeding for fry

• Days 1–5 after they swim freely: infusoria or paramecium, several times a day.
• From days 3–5: microworms or vinegar eels as an extra.
• From days 5–7: newly hatched brine shrimp, the best food for growth.
• Weeks 3–4: water fleas (Daphnia or Moina) and grindal worms.
• Weeks 4–6: start introducing quality pellets or fry powder.

Water quality and growth

• First week: avoid water changes; just top up a little water at the same temperature to replace evaporation.
• From the second week: change 10–20% of the water every day or every other day, and increase gradually as the fry grow.
• Siphon waste slowly with airline tubing so the fry are not sucked up.
• Keep the container covered until the labyrinth organ develops, at about weeks 3–6, so the fry do not breathe cold air.
• Move the fry to a larger container at weeks 2–3 to reduce crowding.
• Separate the young that grow much bigger so the smaller ones still get food.

Separating the young

• Color starts to show and males start attacking each other at about 6–10 weeks.
• Move each male to his own jar or bottle when fighting or fin damage starts, usually at 8–12 weeks.
• Females can usually stay together in a large container, but watch for aggression.
• Change the jar water regularly, for example 50% several times a week or 100% once a week, with water at the same temperature.

Selection and record keeping

Selection decides the quality of the next generation. Judge the young against the standard of the variety you are aiming for.

• Fin shape and spread, symmetry, body shape, color evenness, and pattern.
• Health and liveliness.
• Record the breeding pair, the spawn date, the number of eggs, fry, and survivors, and the best traits of each young fish.
• Young that do not meet breeder standards still make good pets and can go to hobbyists.

Common problems and fixes

• The male builds no nest: the water is too cold, there is current, or the male is not mature. Raise the temperature to 27–28 °C, switch off the filter, add a nest anchor, and give him time.
• No spawning after 3 days: separate the pair, condition them again for 1–2 weeks, then try again or change partners.
• Eggs are eaten: common with young males and with stressed or hungry fish. Reduce disturbances and try again after conditioning.
• Fuzzy eggs: those eggs were not fertilized. Keep the water clean and use Indian almond leaves.
• Fry die in the first week: usually from starvation, rotting leftover food, or temperature swings. Prepare micro food early, feed small portions, and keep the temperature steady.
• Fry gasp or die at weeks 3–4: the air above the water is too cold. Make sure the container is covered.
• Fighting injuries: separate the males earlier.

Welfare and ethics

• Breed only healthy fish without inherited defects.
• Plan where the young will go before you spawn, because one spawn can produce hundreds of fish.
• Never release bettas into the wild; released ornamental fish can harm ecosystems.
• Give breeders enough rest between spawns.

Timeline from preparation until the young are ready

Questions and answers