How Much Do Baby Betta Fish Eat

Newly hatched betta fry are microscopic, roughly 3, 4 mm long, and cannot eat anything larger than their mouth. For the first 3, 4 days they absorb their yolk sac, so you don’t need to feed them at all. Once the yolk is gone and they become free-swimming (day 4, 5), they need food small enough to fit their tiny mouths.

Infusoria, a culture of microscopic organisms like paramecium and rotifers, is the standard first food. You can also use liquid fry food designed for egg-layers. The key is particle size: anything larger than 50 microns is too big.

Feed a few drops of infusoria per 50 fry every 2, 3 hours during daylight.

Frequency matters more than quantity in the first two weeks. Betta fry have high metabolisms and tiny stomachs. I recommend feeding them every 3, 4 hours, 5, 6 times a day, from day 4 to day 14.

After that, you can drop to 4 feedings daily. Miss a feeding and they may eat each other or slow growth. Stick to a strict schedule, morning, mid-morning, early afternoon, late afternoon, evening, and a last feed before lights out.

Each feeding should last only as long as the fry actively chase and eat the food. If food remains uneaten after 5 minutes, you’re giving too much.

Infusoria is added by the drop, not the spoon. For a typical spawn of 100, 200 fry, 3, 5 drops of a dense infusoria culture is enough per feeding. You want the water to look slightly cloudy but not milky.

If it clears within an hour, add another drop. Too much infusoria rots and spikes ammonia, which kills fry fast. The goal is a constant, thin supply, think of it as a living soup they graze on.

You can also introduce green water (phytoplankton) as a supplement; a few milliliters per feeding provides both food and water quality benefits. Rotate between food types once the fry are strong swimmers.

Around day 7, 10, betta fry are large enough to eat newly hatched brine shrimp nauplii. BBS are a major growth accelerator because they’re high in protein. Start with just a pinch, a few dozen nauplii per fry, once daily, alongside infusoria.

By day 14, you can feed BBS exclusively, 4, 5 times a day. The rule: offer only enough that some shrimp remain swimming for 5 minutes before fry lose interest. Overfeeding BBS is common; uneaten nauplii die quickly and foul the water.

Use a turkey baster to siphon out any leftover shrimp an hour after feeding.

Use this simple table to gauge daily portions. Adjust based on fry size and appetite, smaller spawns may need less, larger spawns slightly more.

The takeaway: portion sizes increase gradually, but frequency drops as fry grow. Never feed more than the table suggests, water quality is the biggest killer at this stage.

The most obvious sign is a white, fuzzy film on the water surface or cloudy water after a feeding. Leftover food decomposes quickly, creating ammonia spikes that stress or kill fry. You might also see fry swimming near the bottom with clamped fins, a classic stress response to poor water.

Another red flag: snails or detritus worms appearing in large numbers. If you notice any of these, skip one feeding, do a 10% water change, and cut the next portion by half. Healthy fry should have round bellies after eating but not distended.

A swollen gut that doesn’t shrink between feedings means you’re giving too much.

Underfed fry look transparent around the belly, move slowly, and may hang near the surface without actively chasing food. They can also develop a concave belly rather than a rounded one. In severe cases, fry will nip at each other’s tails or fins.

Growth stunting is the long-term consequence, underfed fry take weeks longer to reach juvenile size. A simple check: after a feeding, watch their bellies. If every fry shows a pale, rounded abdomen within 10 minutes, they’re getting enough.

If half still look flat, increase the amount slightly.

Liquid fry foods like Hikari First Bites or Microbe-Lift Artemia have particle sizes under 50 microns and work well from day 4. For a more natural option, culture your own infusoria using a jar of lettuce or hay water, it’s free and reliable. Once fry reach 2 weeks, crushed high-quality betta pellets (like Omega One or New Life Spectrum) work if you grind them into a fine powder.

Avoid adult-size flakes early on; they’re too big and the debris fouls water. Frozen baby brine shrimp and cyclops are excellent for older fry. The best approach is rotation: alternate live and prepared foods to cover nutritional gaps.

First-time breeders often overfeed, thinking more food equals faster growth. It doesn’t, it causes bacterial blooms that wipe out a spawn overnight. Another mistake: feeding the same food for too long.

Fry need increasing particle size as they grow; sticking with infusoria past day 10 leads to malnutrition. A third error is ignoring water temperature. Betta fry need stable 80, 82°F to digest food properly, cold water slows their metabolism and food rots in their guts.

Finally, never feed live food from unknown sources. Wild-collected infusoria can carry pathogens. Always start cultures from a reputable source or a homemade starter.

Betta fry can transition to adult-sized pellets or flakes around week 8, 10, depending on growth rate. But not all fry grow at the same pace. Judge by size, not age: once a fry’s body length exceeds 1.5 inches (including tail), you can try offering small pellets.

Even then, soak the pellets for a minute first to soften them. Some fry prefer frozen bloodworms or daphnia at this stage, offer those as a bridge food. The full switch to an adult diet usually happens by week 12.

During the transition, continue 3 feedings a day. Watch for any refusal; if they spit pellets out, go back to crushed food for a few more days.