Grow-out walkthrough 02
Tilapia grow-out — choosing between ponds, cages and tanks before pricing
A freshwater project has a production target but no agreed system. Quotes for cages, pond aeration and a tank system cannot be compared because each assumes a different farm.
Planning basis
- System options
- Earthen ponds, lake or reservoir cages, or tank / partial-reuse
- Planning inputs
- Annual tonnes, harvest weight, water temperature profile, water source
- Benchmarks used
- FCR 1.4–1.8, grow-out density 15–40 kg/m³ in tanks, 60–120 kg/m³ in cages
- Critical constraint
- Water availability, temperature season and market harvest weight
How the project is worked
1 · One production target, three system models
The same annual tonnage is modelled as ponds, cages and tanks so land, water, energy and capital intensity are compared before any supplier is contacted.
2 · Temperature decides the calendar
Monthly water temperature sets growth rate and therefore how many cycles fit in a year. A single annual average hides months where fish barely grow.
3 · Fingerling supply resolved
Sex-reversed or monosex fingerling supply, size at stocking and transport are settled before grow-out equipment is specified, because they change the nursery scope.
4 · Scope frozen, then quoted
Only after the system is chosen does the RFQ go out — same battery limits, same incoterm, same spare parts and commissioning scope for every supplier.
5 · Compared on cost per kilogram
Offers are compared on installed cost plus modelled energy, feed and labour per kilogram, so a cheaper package with higher running cost is visible.
What the RFQ must price
- Tanks, cages or pond earthworks with stated materials and design life
- Aeration or water exchange duty at peak biomass and summer temperature
- Pumping: flow, head, standby capacity
- Feeding, grading and harvest handling equipment
- Water quality monitoring and alarms
- Fingerling nursery scope, if within battery limits
- Installation, commissioning, training and spare-part package
Where these projects go wrong
- Comparing a cage quote with a tank quote as if they were the same project.
- Using an annual average water temperature instead of the monthly profile.
- Ignoring harvest weight differences between target markets.
- Assuming fingerling supply exists locally at the required volume and quality.
Run these before briefing suppliers
These are illustrative grow-out walkthroughs, not client case results. They show how a project of this type is sized and taken to a human-reviewed RFQ. No client or supplier is identified, no prices are published, and no yield, cost or delivery outcome is claimed. Biological and cost assumptions require validation by a qualified specialist.