Live Artemia Biomass Recipe

Sanitize and prepare seawater

Fill the clean culture container with 50 L of filtered seawater. Measure salinity with a hydrometer or refractometer and adjust to 30–35 ppt by dissolving additional sodium chloride if needed. Add 5 g sodium bicarbonate to buffer alkalinity. If municipal water was used, add 0.5 g sodium thiosulfate to neutralize residual chlorine. Stir gently until fully dissolved and stable.

Temperature and pH

Bring the water temperature to 25–28°C (use heater or allow to equilibrate). Check pH and confirm it is between 7.8 and 8.5. Make minor adjustments if necessary (bicarbonate will help maintain pH).

Pre-clean cysts (optional)

If cysts are dusty, lightly rinse by placing them in a small mesh and rinsing with clean seawater quickly. Do not soak for long to avoid losing viability.

Hydration and hatch setup

Measure 100 g Artemia cysts. Sprinkle the cysts evenly on the aerated seawater surface in the culture container. Provide continuous, vigorous but not overly strong aeration to keep cysts suspended and oxygenated while avoiding foam that traps cysts. Maintain temperature 25–28°C and constant lighting (12–24 h light) to encourage synchronous hatching.

Hatching period

Allow cysts to hydrate and hatch for 24–36 hours. Monitor progress: viable nauplii will begin emerging after ~18–24 hours depending on temperature and cyst quality. Continue gentle aeration and maintain salinity and temperature.

Initial feeding (first 24–48 h)

Once a substantial fraction of cysts have hatched, begin feeding: dissolve 50 g microalgae paste and 2.5 g dry yeast into a small volume of seawater and disperse evenly. Feed in small doses twice per day to keep water slightly cloudy but not fouled. Maintain aeration and temperature 25–28°C.

Ongoing feeding and water management (days 2–7)

Over the next 3–6 days, feed daily with the remainder of the microalgae paste (total ~200 g used gradually) and an additional 2.5 g yeast per day for the first 3 days. If using commercial Artemia feed or vitamins, add 5 g total divided across feedings. Monitor water quality: if ammonia or waste accumulates (cloudiness with bad smell), perform a 10–20% water exchange with equivalent-temperature, salinity-matched filtered seawater and resume feeding. Maintain aeration and gentle circulation to keep Artemia in suspension.

Growth endpoint and timing

Depending on feeding and conditions, Artemia will grow from nauplii to larger stages suitable for biomass harvest in 5–10 days. Target average size and density such that harvested wet biomass will approximate 1 kg. Monitor visually: a dense cloud of adult/juvenile Artemia indicates readiness. Avoid overgrowing beyond 10–12 days to prevent water quality collapse.

Concentrate and rinse

Stop feeding 12–24 hours before planned harvest to reduce gut contents and waste. Turn off aeration briefly to allow Artemia to concentrate (or use gentle downward flow). Using the conical decanter or 150–200 µm mesh sieve, scoop or decant Artemia into a clean bucket filled with filtered seawater. Gently rinse several times by pouring fresh, temperature- and salinity-matched seawater through the sieve to remove debris and cyst shells.

Weigh wet biomass

After rinsing and draining, transfer the concentrated Artemia to a pre-weighed container and determine wet weight. Aim for ~1 kg wet biomass. If less than 1 kg, repeat partial harvests or allow culture to continue 1–2 days with careful feeding and water maintenance until yield is reached.

Short-term storage

For immediate use (aquaculture feed), store harvested Artemia in aerated, temperature-controlled seawater at 8–12°C for up to 24–48 hours to slow metabolism. Provide gentle aeration and avoid overcrowding to reduce mortality.

Longer-term preservation (optional)

For longer storage, consider cold-shock immobilization followed by freezing or cryopreservation in accordance with specialized protocols (note: freezing viable Artemia is generally not recommended without cryoprotectant and expertise). Alternatively, process into paste or dry product if required by downstream use.

Sanitation

Clean and disinfect culture equipment, buckets, and sieves after use. Dispose of used culture water according to local regulations or treat to remove nutrients before release.