01 · AquaGrow
What it is
Live algae are managed feed cultures, not simply green water. A culture that changes unexpectedly needs a quality check before use. The correct response depends on the algal species, culture system and receiving larval stage.
Signs to watch for
- Unexpected colour, density or settling changes.
- Unwanted organisms or debris are seen under the microscope.
- Growth slows or the culture collapses.
Common causes
- Contamination enters through water, air, vessels or handling.
- Light, temperature, nutrients or other culture conditions become unsuitable.
- Culture identity, age or transfer records are unclear.
How to confirm the cause
- Check culture identity, density and condition by the established laboratory method.
- Review water, light, temperature, transfers and sanitation; identify all larval tanks already supplied.
What to do immediately
- 1
Hold the suspect culture from feeding until checked; label it and keep its records.
- 2
Ask the live-feed specialist to assess it and arrange a verified suitable replacement feed plan.
- 3
Trace any supplied tanks and check larval condition without assuming the algae caused every sign.
- 4
Do not try to rescue the culture with an untested chemical or transfer it into clean starter cultures.
Prevention: your practical checklist
- Separate clean starter cultures from mass production.
- Use dedicated, clean equipment and controlled water and air.
- Record transfers, culture identity and release-quality checks.
When to call an expert
- Seek urgent help if larvae decline after receiving the culture or no suitable feed supply is available.
- Investigate repeated culture failures rather than reusing suspect material.
Farmer questions
Is a strong green colour enough for release?
No. Colour alone does not confirm culture identity, cleanliness or feeding suitability. Use the live-feed unit’s quality checks.
Should I stop all larval feeding?
Do not leave feeding stages without a plan. Hold the suspect feed and ask the specialist to arrange a verified suitable alternative for that stage.
Can a suspect culture be used to start another one?
Do not use it as a clean starter. Keep it separate and follow the laboratory’s investigation and restart procedure.
Sources & further reading
AI-assisted educational content and translations, source-checked 17 October 2026. Not an individual diagnosis or prescription. Independent aquaculture-health and native-language specialist approvals have not been supplied. Sources do not endorse AquaGrow.
- SHAPHARI hatchery operating guidelines — production, biosecurity and records ↗MPEDA; linked guideline, not AquaGrow certification or a legal-compliance audit
- Hatchery operations and assessment framework (2007) ↗FAO FTP 446; historical P. monodon manual, not a vannamei treatment protocol