Inside a closed-loop fish farm: 3 kWh, 0 chemical fertilizer, 2 cash crops

Most aquaculture systems are built to grow fish and discharge water. Most fertilizer factories are built to manufacture chemistry from gas and rock. Our container does neither. It grows fish, captures their manure as a live-microbial culture, polishes the water, and recycles every drop. The fish leave by truck. The fertilizer leaves by drum. The water stays inside.

If you are an agronomist, a controlled-environment agriculture operator, or a technically curious farmer, this is the post that goes inside the box. We will be specific about how it works, why it works on so little energy, and what makes the resulting fertilizer different from anything synthetic.

The system in one paragraph

A 40-foot container houses fish tanks, a biofilter and microbial digester, an oxygenation loop, a manure collection layer, and an IoT control unit. Catfish grow inside on organic feed. Their manure settles, gets captured, and is processed into a live-microbial liquid extract - Magic Power. The water is biofiltered and recirculated 100 percent; the system tops up only the volume that leaves with the extracted fertilizer. Fish output is around 5,000 kg every three months. Fertilizer output ramps with biomass, peaking at around 2,000 liters per day at steady state. Total energy draw: roughly 3 kWh per day.

Now the parts.

Why it runs on three kilowatt-hours

People who have built recirculating aquaculture systems before usually push back on the energy number first, because RAS facilities they have run draw orders of magnitude more. The difference is in the design choices.

• The footprint is small. A single 40-foot container, not a warehouse. There is no room for inefficient pumping or oversized chillers.
• The biofilter is biological, not mechanical. A live microbial community does the bulk of the ammonia conversion work, which means we are not running aggressive aeration or expensive UV.
• The water recirculates 100 percent. We are not pumping fresh water through the system, treating it, and discharging it. The only top-up is the volume that leaves as fertilizer.
• Climate control is modest. Catfish are tolerant of a wide temperature band, which removes the largest energy draw of most CEA systems.
• The control system is event-driven, not always-on. Pumps, sensors, and valves run on duty cycles tied to actual biomass and feed events, not to a constant schedule.

Three kilowatt-hours per day is roughly what a household refrigerator pulls. That number is the single most surprising thing about the system to most engineers, and it is what makes deployment economics work in places where grid power is expensive or unreliable. A container can run on a small solar array with battery backup if the local grid is a problem.

The water cycle, in one loop

Here is what is happening inside, in the order water moves through it:

1. Fish tanks. Catfish at varying biomass classes - from juveniles to harvest-ready - housed in sub-tanks for size sorting and uptime.
2. Solids capture. Manure and uneaten feed settle into a collection layer. This is the raw material for Magic Power.
3. Biofilter. A live microbial bed converts ammonia (from fish respiration) to nitrite and then nitrate. Standard nitrification, but biological rather than mechanical.
4. Oxygenation. A small oxygen injection step keeps dissolved oxygen in the right band for the fish.
5. Return to tanks. Polished water returns to the fish tanks. The loop closes.

What does not happen in the loop is just as important. There is no discharge of nitrogen-rich water into a drain. There is no chlorine or chemical sterilization. There is no mass die-off of beneficial bacteria. The biology that grows the fish is the same biology that ends up enriching the fertilizer, which is the same biology that lands on your soil. It is one continuous, alive system.

The Magic Power side: live microbes, not chemistry

This is where the system stops looking like aquaculture and starts looking like fertility infrastructure.

The captured manure layer is not packaged and shipped. It is processed - aerobically, with a live microbial community already established - until the resulting liquid is a stable, concentrated, live-microbial extract. We bottle that into 30 L jerricans for smaller farms and 220 L drums for cooperatives and anchor operators. Application is 1 liter per 1,000 liters of irrigation water, through any standard fertigation line.

What is in a liter of Magic Power that is not in a liter of synthetic NPK? (Full breakdown: what's actually in 1 liter of Magic Power →)

• Live beneficial microbes. Not preserved spores - active, growing cultures. Bacteria, fungi, and the protists that move nutrients between them.
• The enzymes those microbes produce. Cellulases, proteases, phosphatases - the molecules that unlock nutrients already present in your soil but locked in unavailable forms.
• Macro and micro nutrients in biological balance. NPK is present, but so is the full carbon-nitrogen ratio that makes it usable. Trace minerals come along for the ride.
• Metabolites and signaling molecules. The compounds that beneficial microbes use to communicate, to suppress pathogens, and to recruit plant-microbe symbioses.

Synthetic NPK is a salt. It is delivered to the plant. The plant takes what it can. The rest leaches, volatilizes, or accumulates in the soil as residue. Over years, that residue suppresses the soil's biological activity.

Magic Power is alive. It is delivered to the soil. The soil colonizes, multiplies, and integrates with whatever biology is already there. Over years, the soil gets more active, not less. Water infiltration improves. Organic carbon climbs. The same hectare needs less of everything to perform.

The simplest way to tell a synthetic fertilizer apart from a live one: a synthetic feeds the plant once. A live one feeds the soil for years.

The fish side: 5,000 kg per quarter, hospitality-grade

The fish revenue line is not a side product. It is the second cash crop, and it is what gives the system economic resilience.

Production is roughly 5,000 kg every three months per container, or about 20,000 kg per year. The fish are catfish - well-suited to the closed-loop environment, fast-growing, and remarkably versatile in the kitchen. They are raised on organic feed without antibiotics or growth hormones.

We sell them under the Organic Gattuccio brand into hospitality. Year-round consistency is the point. Restaurants - especially the Michelin-aligned ones - cannot build a menu around a wild-catch fish that arrives in pulses and disappears for a month. Gattuccio shows up on the same day every week, in the same size grade, with the same provenance papers.

Chef Diego Della Schiava at The View Lugano uses it across his Mediterranean menus. Chef Pasquale Laera plates it at the Michelin-starred Borgo Sant'Anna. Matteo "Teo" Canzi, the MasterChef Italia 2026 winner, used catfish in his winning dish. The hospitality channel is not theoretical - it is the exact channel that funds the second revenue line in our deployment math.

For more on that side of the system, see Organic Gattuccio.

The IoT layer: telemetry, not theater

The container is monitored continuously. Not in a marketing sense - in a "the dashboard shows you the dissolved oxygen at 3 a.m." sense.

What the IoT layer captures, on standard schedules:

• Water temperature, dissolved oxygen, pH, ammonia, nitrite, nitrate, conductivity.
• Pump runtime, biofilter performance, oxygen injection rate.
• Feed events, biomass estimates, mortality flags.
• Fertilizer collection volume, processing tank levels, output batch numbers.
• Energy draw and grid status.

Every container reports to a central dashboard. Operators can run multiple containers from one screen. Anomalies trigger alerts before they become problems - a slow drift in dissolved oxygen, for example, surfaces hours before it would be noticed by a worker on a daily round.

For an agronomist, the data trail is more valuable than the alerts. Every batch of Magic Power that leaves the system carries a timestamped batch ID linked to the conditions under which it was produced - feed batch, biomass, water chemistry. That is full traceability from container to drum to soil. It is what allows us to keep tightening the production process over time, and it is what makes Magic Power a credible input for serious controlled-environment growers.

The full system architecture is described at the system.

The IP heritage: where the container came from

The containerized aquaculture technology is licensed from Hosha Holdings, a South African group that spent years developing and refining the closed-loop design before our deployment. The containers are built in South Africa and shipped to destination - a logistics decision driven by manufacturing depth and quality control, not by chasing the cheapest fabricator.

Hosha Holdings' contribution is the system architecture: the integration of fish tanks, biofilter, manure capture, and water recirculation in a 40-foot footprint. Hosha Vitality - the operator brand behind Rosso & Scanavino Family Farms - holds the license, runs the deployments, and built out the Magic Power processing and brand layer on top. The chef partnerships and the Organic Gattuccio brand are the operator's, too.

This split matters because it answers the question every agronomist asks early: who actually built this, and have they done it before. The answer is yes - the IP origin is a multi-year R&D track in a comparable arid-agriculture environment, and the units that have been operating longest are now well past the early-failure window.

What you cannot see in the spec sheet

A few things that do not show up in the diagrams but matter in the day-to-day:

• One worker can run multiple containers. The system is designed for low-supervision operation. A site with ten containers is not a ten-person facility.
• The footprint is genuinely small. A 40-foot container plus a small service area. You can deploy on a corner of an existing farm.
• The startup curve is real. Fish biomass takes months to reach steady state, and fertilizer output ramps with biomass. The first year is not the steady-state year, and we plan deployments accordingly.
• The biology is forgiving but not bulletproof. Live systems do not like sudden chemical shocks. The standard operating procedure is straightforward, and the IoT layer catches drift early, but operators need to respect that this is a living system.

The summary, for the technically curious reader

• A 40-foot container produces both fish and live-microbial fertilizer, on 3 kWh per day.
• Water recirculates 100 percent; only the extracted fertilizer volume is replaced.
• Magic Power is a live culture, not a synthetic - microbes, enzymes, and balanced nutrients in one liter, applied at 1 L per 1,000 L in irrigation water.
• Fish output is about 5,000 kg per quarter, into a hospitality channel led by named chef partners.
• Every container is fully instrumented; batch traceability is end-to-end.
• The IP comes from Hosha Holdings; the operator brand is Hosha Vitality, the family operating company behind Rosso & Scanavino Family Farms.

If you want to see the system in person, walk a deployment site, or run your own crop trial alongside our biology, the right next step is to apply for a container or to talk to a deployment lead. We will set up a site visit and a soil test.

For the full product side, see Magic Power and the system.

See also: our soil-science library.