Knowledge
The Engineering Behind Modern Recirculating Aquaculture.
Explore the science, engineering, operation and technology behind high-performance Recirculating Aquaculture Systems — from culture tanks and filtration to biofiltration, oxygen management, water quality, automation and commercial production.
Featured guides
Four places to begin, depending on whether you are approaching the subject as a newcomer, a designer or an operator.
RAS Fundamentals
A recirculating aquaculture system treats and reuses its own water. This is the loop, the reason each stage exists, and the conditions under which the approach earns its cost.
Biofiltration
The biofilter is a cultivated bacterial population that converts ammonia to nitrate. It is the one unit process that cannot be bought and installed on the day it is needed.
Oxygen Management
Oxygen is the only parameter in a recirculating system with a time to mortality measured in minutes. Everything about its design and monitoring follows from that.
Water Quality
Water quality is not a list of independent numbers. The parameters move each other, and reading any one of them in isolation is the most common analytical error made on a recirculating farm.
Explore RAS engineering
Thirty areas, in the order an engineer would work through them: principles first, then the unit processes, then the biology, then the plant and the business around it.
- 01Beginner8 min read
RAS Fundamentals
What a recirculating system is, how the loop works, and where it fits.
- 02Intermediate7 min read
System Architecture
Process flow, loop configuration, redundancy and biosecurity zoning.
- 03Intermediate7 min read
Culture Tanks
Geometry, inlets, drains, flow patterns and self-cleaning behaviour.
- 04Intermediate6 min read
Hydraulics
Flow, turnover, retention time, head loss and where the energy goes.
- 05Intermediate7 min read
Mechanical Filtration
Drum filters, separators and settlement — taking solids out while they are still solids.
- 06Advanced8 min read
Biofiltration
Nitrification, media, reactor types, startup and the ways a biofilter fails.
- 07Intermediate6 min read
TAN and Ammonia
Where ammonia comes from, what makes it toxic, and how much a system produces.
- 08Intermediate6 min read
Solids and TSS
Solids production, particle size, loading and sludge handling.
- 09Advanced7 min read
Oxygen Management
Demand, transfer, supply, and the failure that kills fastest.
- 10Advanced7 min read
Degassing and CO2
Carbon dioxide accumulation, stripping, nitrogen supersaturation and degasser placement.
- 11Advanced7 min read
UV and Disinfection
UV dose, ozone, ORP, and the difference between disinfection and sterilisation.
- 12Intermediate6 min read
Water Quality
Every parameter: what it is, how to measure it, and how it interacts with the rest.
- 13Intermediate6 min read
Fish Biology
Metabolism, growth, excretion, stress and the numbers that describe them.
- 14Intermediate6 min read
Murrel and Channa
Species-specific culture knowledge for murrel in recirculating systems.
- 15Intermediate6 min read
Feed Management
Feed rate, conversion, quality, scheduling and waste.
- 16Intermediate5 min read
Biomass Management
Standing biomass, sampling, grading and production forecasting.
- 17Advanced5 min read
Fish Health and Biosecurity
Quarantine, handling, prevention and mortality investigation.
- 18Advanced6 min read
Automation
Sensors, control, alarms, logging and fail-safe behaviour.
- 19Advanced6 min read
AI in Aquaculture
What is deployed, what is in research, and the line between the two.
- 20Intermediate5 min read
Energy
Where the power goes, and what it costs to keep water moving and fish alive.
- 21Advanced6 min read
Economics
Capital, operating cost, margin and the assumptions behind every model.
- 22Intermediate6 min read
Farm Design
Site, building, rooms, movement and biosecurity zoning.
- 23Intermediate7 min read
Piping
Materials, sizing, layout, valves and the joints that decide reliability.
- 24Advanced6 min read
Pumps
Types, curves, duty point selection, cavitation and redundancy.
- 25Advanced7 min read
Electrical
Supply, distribution, standby power, protection and wet-environment safety.
- 26Intermediate6 min read
Operations
Daily routine, records, staffing, procedures and the discipline that holds them.
- 27Advanced6 min read
Troubleshooting
Diagnostic method, symptom-to-cause ordering and stabilise-before-diagnose.
- 28Advanced6 min read
Commissioning
Water testing, biofilter maturation, first stocking and handover.
- 29Advanced7 min read
Failure Modes
How systems fail, how fast, and what protection is worth having.
- 30Intermediate7 min read
Safety
Hazards to people: electrical, chemical, gas, confined space and drowning.
Latest knowledge
The most recently published areas.
Safety
Hazards to people: electrical, chemical, gas, confined space and drowning.
Failure Modes
How systems fail, how fast, and what protection is worth having.
Commissioning
Water testing, biofilter maturation, first stocking and handover.
Troubleshooting
Diagnostic method, symptom-to-cause ordering and stabilise-before-diagnose.
Operations
Daily routine, records, staffing, procedures and the discipline that holds them.
Electrical
Supply, distribution, standby power, protection and wet-environment safety.
Explore by topic
The same thirty areas, grouped by the discipline they belong to. Several appear under more than one, because the subject does not divide cleanly.
Water
Engineering
Operations
- RAS Fundamentals
- System Architecture
- Solids and TSS
- Oxygen Management
- UV and Disinfection
- Water Quality
- Fish Biology
- Murrel and Channa
- Feed Management
- Biomass Management
- Fish Health and Biosecurity
- Automation
- AI in Aquaculture
- Energy
- Economics
- Farm Design
- Piping
- Pumps
- Electrical
- Operations
- Troubleshooting
- Commissioning
- Failure Modes
- Safety