The chain: from feed load to connected power
Everything downstream follows from how much feed enters the system each day at peak standing biomass. Feed drives oxygen consumption, ammonia excretion and solids production; those three drive the treatment train; the treatment train drives flow, head and power.
- ·Standing biomass and stocking density by production unit
- ·Peak daily feed and FCR, converted to oxygen demand and TAN production
- ·Water exchange or recirculation rate, and the resulting total flow
- ·Mechanical filtration duty — solids load, screen area, backwash water
- ·Biofilter media volume from TAN load and specific removal rate
- ·Oxygenation and degassing duty, plus CO₂ stripping where relevant
- ·Pump head across the loop, and total connected kW for the OPEX model
Why brochure sizing fails
Manufacturer literature is written around standard model ranges, which are sized for a typical species, temperature and density. Change the temperature by four degrees or the density by fifteen kilos per cubic metre and the standard model is either undersized or a permanent waste of energy. Sizing from your own duty figures makes those mismatches visible before you pay for them.
Cost and energy come from the same numbers
The duty figures also produce the operating model: kWh per kilogram, oxygen cost, feed cost, and the cost per kilogram that decides whether the project is bankable. A capital quote without the matching energy figure is only half of the price.
Guides that explain the calculations
The filtration and sizing guides below walk through the same chain in detail, with the units and rules of thumb used in commercial projects.
How to size a fish farm or shrimp farm, step by step
Sizing is a chain, and every link depends on the one before it. Peak biomass sets peak daily feed. Feed sets oxygen demand, ammonia output and solids. Those three set aeration or oxygenation duty, mechanical filtration area and biofilter volume. Flow and head set pump duty, and the sum of all duties sets connected power — which is why the electricity question cannot be answered before the biology is settled.
Buyers often ask how many tanks or ponds they need for a target tonnage. The honest answer is that tank count is an output, not an input: it falls out of density limits, harvest logistics and grading strategy once the biomass curve is drawn. A supplier who quotes a package before asking about your peak feed load is selling a catalogue, not designing a farm — and two catalogues can never be compared.
- ·Biomass curve first, then feed load, then every derived duty
- ·Size for the worst week of the year — temperature and biomass together
- ·Treat every figure as a procurement planning estimate, not detailed engineering