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Brine shrimp for baby fish

The short answer: newly hatched brine shrimp nauplii are the classic first food for tiny fry — small enough for the smallest mouths, swimming enough to trigger a feeding response, and rich in the yolk-sac nutrition fry need. Hatch them in saltwater with strong aeration and light, and they're ready in 24 to 36 hours.

Why nauplii, and why newly hatched

Fry of bettas, tetras, guppies, and many other species are too small for even powdered foods at first, and they respond to movement — a swimming nauplius gets eaten, a sinking particle often doesn't. Nauplii are most nutritious in their first hours after hatching, while they still carry their yolk sac, so hatch small batches often rather than one big batch rarely.

Hatching setup

  1. Saltwater: mix marine salt to a specific gravity around 1.018 (roughly a tablespoon of salt per liter of dechlorinated water is a workable starting point; a hydrometer removes the guesswork).
  2. Temperature: around 80°F hatches fastest; cooler water works but takes longer.
  3. Aeration: strong, from the bottom, so the eggs stay suspended and don't settle — settled eggs hatch poorly.
  4. Light: keep a light on the hatching container; light improves hatch rates.
  5. Time: most eggs hatch in 24 to 36 hours at the right temperature.

Harvest: light does the sorting

When it's time to feed, stop the air and shine a light at the bottom of the container. Nauplii swim toward light and gather there, while unhatched eggs and shells mostly float or sink elsewhere. Siphon the gathered nauplii through a fine brine shrimp net, rinse them briefly with fresh water, and feed them right away — rinsing matters, since you don't want to pour saltwater into a fry tank.

How much to feed

Feed small amounts several times a day, and only what the fry eat in a few minutes. Overfeeding fouls a fry tank fast — uneaten nauplii die, decay, and spike ammonia, which kills fry quicker than slight underfeeding does. If you see uneaten shrimp accumulating, cut the portion and siphon the bottom. As fry grow, graduate to adult brine shrimp and to copepods, which suit larger fry and juveniles.

Order the feeders in this guide

Nano Brine Shrimp Portion (from)

Nano Brine Shrimp - Portion (from)

$12.99 FREE shipping

Live nano brine shrimp for fry, nano fish, and filter feeders. Highly perishable — shipped same-week only....

5280 Pods - 3-Species Mix 16 oz jar

5280 Pods - 3-Species Mix - 16 oz jar

$50.99 FREE shipping

The flagship three-species copepod blend — 5,280+ pods per jar — for reef tanks that need a diverse, self-sustaining pod population....

You order here; we place your order with the breeder, and the breeder ships direct to you. Live arrival is covered within the supplying breeder's window — see our live arrival policy. General keeper guidance only, not veterinary advice: if your animal is sick, not eating, or losing weight, see a reptile or aquatic vet.