Nursery Stage: Weaning, Grading & Transfer Specification
The nursery decides what the grow-out actually receives. Transfer size, uniformity, health status and batch timing are procurement variables, not biological details to settle later.
What does the nursery stage cover in a commercial project?
The nursery takes weaned larvae or post-larvae and grows them to a robust transfer size for grow-out. It covers weaning protocol, tank or raceway capacity, grading and size sorting, feeding and water-quality management at rising biomass, health screening, acclimation to grow-out conditions, and batch scheduling so the grow-out can be stocked on plan. Procurement needs transfer size, uniformity tolerance, survival assumptions and batch volumes stated in writing before equipment is sized.
Scope to define before sourcing
Weaning protocol
Stage at which live feed is withdrawn, diet sequence, particle sizes, feeding frequency and the water-quality consequences of higher feed loading.
Tank and raceway capacity
Nursery volume derived from transfer size, batch volume and target density, with sufficient units to keep cohorts separated and allow full disinfection between batches.
Grading and uniformity
Grading frequency and method, handling stress limits, and the size uniformity tolerance you will accept at transfer — state it as a range, not an average.
Water quality at rising biomass
Oxygen and ammonia loading grow quickly in nursery. Size treatment, aeration and exchange for end-of-cycle biomass, not average biomass.
Health screening and acclimation
Screening points before transfer, treatment records, and controlled acclimation to grow-out temperature and salinity to limit post-transfer mortality.
Batch scheduling
Number of cohorts per year, cycle length and turnaround time between batches, aligned with the grow-out stocking calendar.
Decisions and the evidence to request
| Decision | What to compare | Evidence in the RFQ |
|---|---|---|
| Transfer size | Smaller, cheaper juveniles versus larger, more robust transfers | Target weight or stage, uniformity tolerance and expected survival after transfer |
| Nursery location | Inside the hatchery, at the grow-out site, or contracted out | Transport distance, acclimation plan and who carries mortality risk in transit |
| System type | Flow-through raceways, recirculating nursery or hapa/tank hybrid | Design density, treatment duty at peak biomass and disinfection turnaround |
| Batch plan | Continuous production versus discrete cohorts | Monthly batch schedule, cohort separation and cleaning window between batches |
RFQ checklist
- Transfer size and uniformity tolerance
- Batch volumes and monthly schedule
- Design density and end-of-cycle biomass
- Survival assumption used for sizing, stated as a range
- Grading method and handling limits
- Health screening points and records required
- Acclimation protocol to grow-out conditions
- Cleaning and disinfection turnaround between cohorts
Where this stage sits
- 01
Planning
Species, juvenile output by month, water source, site and procurement assumptions.
- 02
Species & seed
Seed specification, broodstock provenance, health status and documentation to request.
- 03
Hatchery systems
Broodstock, incubation, larval tanks, live feed, water treatment and biosecurity scope.
- 04
Nursery
Weaning, grading, nursery density, survival assumptions and transfer size.
- 05
Grow-out handoff
Match juvenile size, batch timing and volume to the grow-out stocking plan.
- 06
FCR & feed
Test conversion, feed budget and the economic impact of FCR before sizing feed supply.
- 07
Equipment
Build one package across pumping, filtration, oxygenation, controls, live feed and dispatch.
- 08
Cost
Separate civil works, equipment, energy, broodstock, labour, working capital and contingency.
- 09
Financing readiness
Score bankability before approaching independent third-party financing providers.
- 10
RFQ
Issue one controlled hatchery brief so qualified suppliers quote the same scope.
Questions buyers ask
Continue planning
Send the project brief
Share location, species and target production. Every brief is reviewed by a person before any supplier is approached, and supplier identities stay confidential until you approve an introduction.
Short answer
What is the fastest way to get quotes for Nursery?
Submit one structured request for Nursery. FishMatch Group translates it into a technical RFQ, runs a confidential sourcing round with project-matched international suppliers, and returns comparable quotations. No fee is charged to the buyer, and your identity and project details stay private until you choose to proceed.
- How it works:
- One structured request, human-reviewed before any supplier outreach
- Typical turnaround:
- Depends on scope and site data; no turnaround is guaranteed
- Confidentiality:
- Supplier names are never exposed during evaluation
- Cost to buyers:
- No fee charged to the buyer
Before you request quotes
Equipment scope
What equipment does a commercial aquaculture project actually need?
A grow-out project typically needs holding infrastructure (tanks, ponds or cages), water movement (pumps, piping, valves), aeration or oxygenation, water treatment appropriate to the system, feeding equipment, grading and handling gear, monitoring and alarms, and backup power. RAS adds mechanical filtration, biofiltration, degassing, disinfection and tighter process control. Hatchery and processing scopes are specified separately.
Which equipment should be specified before requesting quotes?
Specify the items whose sizing changes everything downstream: design biomass and stocking density, water exchange or recirculation rate, oxygen demand at peak temperature, and installed pumping head. With those four fixed, suppliers can quote aeration, filtration, pumps and power on the same basis. FishMatch calculators produce these figures and attach them to the RFQ.
Can equipment be sourced in stages?
Yes, and phased procurement is common. The usual sequence is water supply and holding infrastructure, then aeration and treatment, then automation and monitoring, then processing and cold chain. Staging works when interfaces and capacity headroom are defined at the start; otherwise later phases force replacement rather than addition.