Best Foods for Baby Fish (Fry): What to Feed at Every Stage

Stage One: Newly Hatched Fry and Yolk Absorption

Right after hatching, fry rely entirely on their yolk sacs for nutrition. This self-contained energy source fuels their first few days of life while they remain mostly stationary. During this time, do not feed them — introducing food too early can foul the water and cause fatal bacterial blooms. Wait until they begin free-swimming on their own; that’s your signal that the yolk sac is absorbed and external feeding can begin. Keeping the water clean, warm, and oxygenated during this phase is far more important than feeding. Once movement increases and fry begin darting for invisible food, it’s time to start the next stage.

Stage Two: The Infusoria Phase (Days 3–7)

This is the most delicate and critical feeding period. Newly free-swimming fry are too small to eat commercial food or even brine shrimp. Their first meals must be microscopic. Infusoria — a mix of tiny protozoa, bacteria, and algae — forms the foundation of early fry nutrition. It’s alive, it moves, and it perfectly fits their mouths. You can culture infusoria easily by soaking a lettuce leaf or banana peel in a jar of aquarium water and leaving it in sunlight for several days. Once the water turns slightly cloudy, it’s teeming with life. Using a pipette, add a few drops to your fry tank several times a day. Infusoria keeps fry active, hydrated, and full of essential nutrients.

Stage Three: Transitioning to Baby Brine Shrimp (Week 1–2)

By the end of the first week, most fry can handle larger, moving foods. Freshly hatched baby brine shrimp (Artemia nauplii) are the best next step. They’re loaded with protein and carotenoids that boost growth and coloration. Their jerky swimming motion naturally triggers the fry’s feeding instinct. Hatch them by mixing brine shrimp eggs with salt water and aerating for about 24 hours. Once hatched, strain them through a fine mesh and rinse in fresh water before feeding to prevent salinity buildup. Offer brine shrimp 2–4 times daily in small quantities. It’s the single most effective food for rapid growth and strong survival.

Stage Four: Introducing Microworms and Vinegar Eels (Weeks 2–3)

At this stage, fry are stronger, hungrier, and ready for variety. Microworms are tiny nematodes that wiggle enticingly, promoting natural hunting behavior. They’re easy to culture at home — just mix oatmeal or baby cereal in a shallow container, add a starter culture, and keep it warm. Within days, the surface will glisten with crawling worms ready to scrape and feed. Vinegar eels, another live food option, thrive in apple cider vinegar solutions and can survive longer in water, giving fry extra time to eat. Alternating between microworms and baby brine shrimp provides balanced nutrition and prevents monotony.

Stage Five: Powdered and Commercial Fry Foods (Weeks 3–5)

Once fry are more visible and swimming freely throughout the tank, you can begin introducing powdered or crushed dry foods. Commercial products like Hikari First Bites, New Life Spectrum Grow, or Omega One Fry Formula are excellent. They contain balanced protein, fats, and vitamins designed for rapid development. To prepare flakes, crush them between your fingers or in a zip-lock bag until they become dust-fine. Sprinkle lightly across the tank’s surface; fry will pick at the tiny particles as they sink. Rotate between live and powdered food to ensure variety and to train fry for future transitions to a standard diet.

Stage Six: Crushed Flakes and Mini Pellets (Weeks 5–8)

By this time, fry are entering the juvenile stage and can handle more substantial meals. Begin feeding crushed flakes or micro-pellets, alternating with live or frozen foods for diversity. Slowly increase particle size as fry grow. Feed 3–4 times daily, but continue small portions to avoid fouling the water. Some species, like bettas or cichlids, will also begin nibbling at small pieces of frozen daphnia or bloodworms by this age. This is the period when growth accelerates — maintaining a high-protein diet ensures strong bodies and vivid coloration.

Stage Seven: Transitioning to a Juvenile Diet (After Week 8)

Once fry resemble miniature versions of adult fish, you can start feeding them similarly — just in smaller amounts. Offer a balanced mix of crushed flakes, frozen foods, and live options like brine shrimp or daphnia. Slowly reduce feeding frequency to 2–3 times per day. Introduce occasional plant-based foods like spirulina flakes or blanched spinach for digestive health. Variety now builds long-term resilience and prepares them for life in the main tank.

Feeding Frequency and Routine

Consistency is key. Fry should be fed small portions 3–5 times daily, depending on species and growth rate. Their metabolism runs fast, and missing meals can slow development. However, overfeeding is equally dangerous — leftover food quickly decays, creating deadly ammonia spikes. Always offer tiny amounts, observe consumption, and clean up excess promptly. Establishing a feeding schedule also helps fry learn predictable routines, reducing stress and improving appetite.

The Power of Live Foods

Live foods remain unmatched for fry growth. Beyond nutrition, movement stimulates natural instincts, keeping fry active and alert. Brine shrimp and microworms are staples, but you can also explore daphnia, rotifers, copepods, or green water cultures for advanced feeding systems. Live food enhances coloration, strengthens muscles, and boosts immunity. The more natural your feeding approach, the healthier and hardier your fry will become.

Avoiding Feeding Mistakes

Many beginners accidentally sabotage their fry with good intentions. The most common mistakes include feeding too early, using food that’s too large, and failing to clean up leftovers. Another common issue is relying on one food type; monotony leads to nutritional deficiencies. Switch between live and dry options for balance. Never assume adult fish foods are suitable — they can choke fry or remain uneaten, rotting in the tank. If the water becomes cloudy after feeding, reduce portion size immediately. Clean water is the invisible ingredient that keeps fry alive.

How to Enrich Food for Better Growth

You can supercharge fry nutrition by enriching live and dry foods. Soak brine shrimp or microworms in vitamin supplements or spirulina solutions before feeding. For dry foods, mix powdered flakes with a few drops of liquid multivitamins. These enrichments strengthen the immune system, improve fin and scale development, and enhance natural coloration. Consistent enrichment over weeks results in noticeably healthier, faster-growing fry.

Adjusting Diet by Species

Not all fry are alike. Carnivorous species like bettas, angelfish, and cichlids thrive on protein-heavy live foods. Omnivorous fry such as guppies, tetras, or mollies need a mix of plant and animal sources. Herbivorous fry, like some plecos, prefer algae-based foods or boiled vegetables early on. Researching your species’ natural diet helps fine-tune feeding and minimizes waste. Matching diet to biology ensures steady, natural growth and reduces stress from unsuitable nutrition.

Signs of Proper Nutrition

Healthy fry show steady movement, clear eyes, rounded bellies after meals, and increasing size every week. Their coloration intensifies as they grow, and they swim confidently throughout the tank. Malnourished fry appear thin, pale, or lethargic. Watch closely for uneven growth; smaller fry might not be getting enough food. If you notice aggression or crowding during feeding, separate fry by size so everyone has fair access.

Maintaining Water Quality During Feeding

No matter how nutritious the food, dirty water cancels all progress. Perform 10–15% water changes daily to remove waste and uneaten particles. Use a soft airline siphon to clean gently without disturbing the fry. Keep filters sponge-based and clean them in tank water weekly. The combination of clean water and high-quality food is the foundation for survival and speed of growth.

When to Reduce Feeding

As fry mature and approach juvenile size, their metabolism slows slightly. You can reduce feeding to 2–3 times daily. Larger, less frequent meals are now sufficient. Continue offering variety — alternating between protein-rich and plant-based foods — to maintain balanced nutrition. Avoid abrupt feeding changes; transitions should take place gradually over several days to prevent digestive stress.

The Joy of Watching Growth Unfold

There’s something remarkable about watching fry evolve through feeding stages. Each meal adds strength, shape, and color. What began as nearly invisible specks become miniature versions of your adult fish, darting confidently through the tank. Feeding isn’t just maintenance — it’s an act of nurturing that connects you directly to life’s smallest miracles. Patience and consistency reward you with healthy, vivid fish that carry your care in every scale and fin.

Feeding for a Lifetime of Health

Feeding baby fish correctly means more than keeping them alive — it means helping them flourish. By matching foods to each growth stage, maintaining clean water, and offering variety, you build a foundation for vibrant, long-lived fish. From the first drop of infusoria to the final transition to flakes, every meal counts. Your dedication turns fragile fry into thriving adults — proof that great aquarists feed not just with knowledge, but with care.