La aquaponicsa system that combines breeding de peces With the cultivation of vegetables using recirculated water, it is beginning to gain ground as a real alternative for the agri-food sector. Its approach to circular economy and efficient use of resources This positions it as an interesting option for rural areas and also for projects near urban areas, where the aim is to produce more with less water and fewer external inputs.
In Spain, especially in Galicia and other Atlantic regions , interest in aquaponics is growing in parallel with concerns about climate change, price volatility , and the need to reduce dependence on traditional extensive farming models. Meanwhile, technical and demonstration projects in European and Latin American greenhouses are providing concrete data on its viability, from leafy greens to less common crops like garlic.
Aquaponics as a means of diversification in the primary sector
The Galician Association of Agri-food Cooperatives (Agaca) has placed aquaponics at the heart of its strategy to explore new business opportunities in the primary sector . In line with its work in recent months, the organization has scheduled a technical workshop focused on two complementary technologies: hydroponics and aquaponics, with the aim of demonstrating how they can complement and diversify Galicia's traditional farming systems.
Agaca emphasizes that the search for more resilient production models is a priority for rural Galicia. The combination of climate change, rising input costs, and price fluctuations has put many extensive farming systems in a precarious position. Therefore, the association is trying to offer its cooperatives options that make better use of natural resources and allow them to adapt to more demanding climate scenarios.
The online event is aimed at cooperative members, those involved in agricultural production, and the general public. The program is designed to inform, evaluate, advise, and guide those considering entering these systems. Participation requires prior registration through the organization's website, a measure intended to organize attendance and facilitate access to the presentations.
During the meeting, specialists will address the topic from different perspectives. The technical foundations of hydroponics will be presented , the key aspects of aquaponics will be explained, and the advantages and disadvantages of these production systems will be analyzed in a balanced way. In addition, a specific hydroponic project in Galicia will be presented, allowing the discussion to be grounded in the realities of the climatic and market conditions of the northwest Iberian Peninsula.
Agaca's interest in aquaponics is also framed within the debate on the potential for cooperative development of these systems . The idea is to explore whether collective scale can facilitate investment in greenhouses, tanks, recirculation systems, and control equipment, so that smaller farms are not excluded from these innovations due to initial costs.
A circular system: fish and vegetables in recirculation
Aquaponics is essentially defined as a closed recirculating system that integrates fish tanks or ponds with growing channels or trays for plants. The fish produce organic waste which, after being transformed by nitrifying bacteria, becomes nutrients that can be used by the plant roots . In turn, the plants absorb these compounds and help purify the water, which returns to the tank in better condition for the fish.
This system mimics the natural balance found in a river ecosystem , but it is applied in a controlled manner in greenhouses or small- and medium-scale facilities. The absence of soil significantly reduces weed growth and, therefore, decreases or eliminates the use of herbicides . If the system is well managed, it can also minimize the need for pesticides by controlling variables such as temperature, water quality, and crop density.
In many projects, the chosen fish species is tilapia , prized for its rapid growth and tolerance to varying water conditions. However, in temperate European climates, it is common to opt for species better adapted to lower temperatures, such as certain varieties of trout or carp, taking advantage of existing fish stocks in rivers and reservoirs.
Aquaponics stands out for its low water consumption compared to soil-based agriculture . Because it's a closed-loop system, losses are primarily limited to plant evapotranspiration and minor maintenance flushes. This makes it a particularly attractive option for areas with water scarcity or aquifers under increasing pressure.
In addition, the system offers a dual marketable productOn one hand, fresh vegetables (mainly leafy greens, herbs, or some fruit crops), and on the other, fish suitable for human consumption. This dual output can improve the model's potential profitability, provided that key aspects such as biosecurity and density are carefully managed. de peces and the nutritional management of plants.
Technical experiences with new crop species
Tests conducted in various greenhouses demonstrate that aquaponics is not limited to classic leafy vegetables like lettuce or chard . Trials carried out by technical teams in demonstration modules have incorporated species that, at first glance, might seem less common in this context, such as garlic (Allium sativum), with very promising results.
In one specific experiment, an aquaponic system was installed inside a glass greenhouse , combining growing trays with plants of a purple garlic variety and a tank with common carp (Cyprinus carpio) . The fish, caught in a nearby river, provided the necessary nutrients for the plants' vegetative development, allowing them to successfully complete their entire growing cycle.
The results showed that garlic can be a very interesting alternative from a commercial standpoint in aquaponic systems. The harvested heads exhibited good post-harvest preservation, allowing for staggered sales and avoiding the urgency associated with other more perishable products, such as lettuce or tomatoes. This ability to store the product for longer periods provides flexibility in adjusting marketing to market prices.
In addition to its economic viability, garlic proved to be a useful addition to the family diet , expanding the variety of vegetables that can be grown in a single aquaponic system. The uniform growth of the plants and the proper formation of the bulbs have led the technicians involved to propose including this crop among the recommended options for simple systems, both in demonstration projects and on small farms.
The use of common carp as a stock species in the test module was positively evaluated for several reasons: its ease of rearing, safety in handling , relatively low feed cost, and the possibility of transforming its meat into a food resource. In this way, a species considered invasive in numerous freshwater ecosystems can become a raw material for efficient production systems , contributing to reducing its environmental impact through a responsible management approach.
Leveraging local resources and improving the circular economy
The idea of ​​resorting to species de peces Already present in nearby ecosystems, such as carp in certain rivers or trout in inland and mountain areas, fits with the philosophy of the circular economy applied to aquaponicsInstead of considering these species exclusively as an ecological problem, some projects propose their use as a productive resource, always within regulatory frameworks that guarantee the protection of native fauna.
Carp meat, for example, carries a somewhat negative social reputation in many places , despite being a freshwater fish with a good capacity for adaptation and culinary potential if handled and prepared properly. Specialized technicians have begun working on specific recipes and preparations that will highlight the value of this product while reducing the pressure the species exerts on fragile ecosystems.
In some demonstration plots, after several months of fattening in aquaponic systems, the fish are processed to determine yields, meat quality, and processing possibilities. This data serves as a basis for future farms to evaluate whether carp or other species production can be a profitable business line to complement vegetable cultivation.
The integrated resource management approach aligns with objectives also set in the European context : reducing waste, increasing resource efficiency, and promoting production models that integrate environmental, social, and economic functions. Aquaponics fits into this framework by generating plant- and animal-based foods with very limited water and nutrient use , while simultaneously offering a valuable demonstration tool for educational and agricultural vocational training centers.
In territories like Galicia, where agriculture coexists with a strong presence of inland water bodies and coastline, adapting these models to local conditions could facilitate projects that make better use of existing infrastructure (warehouses, greenhouses, old fish farms) and systems such as aquaculture networks and allow the addition of new lines of activity to cooperatives and small family farms.
Training, scalability and opportunities for small farms
One of the points most frequently repeated by specialists is the importance of prior training . Learning the fundamentals of hydroponics first—pH management, nutrient solution formulation, temperature control, and oxygenation—makes the transition to aquaponics much easier, ensuring a solid foundation. This reduces initial errors that could jeopardize fish health or plant performance.
The workshops organized by entities like Agaca and other technical centers are specifically designed to address this need. Through talks, in-person courses, and online seminars , the aim is for interested individuals to understand not only the technological aspects but also the economic, regulatory, and day-to-day operational implications of such a system.
The scalability of aquaponics is another of its strengths. It's possible to start with small modules in greenhouses or attached to existing farms, initially intended for family consumption . If the results are satisfactory, these same modules can be expanded or replicated to target direct sales, short supply chains, or even agreements with local shops and consumer cooperatives.
In peri-urban areas of European cities, aquaponics is also being explored as a way to bring fresh food production closer to population centers , thus reducing costs and emissions associated with transportation. This approach could be adapted without too much difficulty to Spanish metropolitan areas, where there is already a growing demand for locally grown vegetables produced sustainably.
The possibility of implementing modular systems makes the model equally attractive for educational centers, farm schools, and vocational training facilities. The combination of biology, chemistry, water management, and agronomic knowledge makes aquaponics a powerful educational tool for bringing science and food production closer to students and people undergoing professional retraining.
Overall, aquaponics is emerging as a versatile technology that can range from small-scale home setups to larger, cooperatively managed installations. Its suitability for contexts like Galicia or other European regions will depend on factors such as the availability of training, access to initial funding, and the ability to integrate these systems into broader rural development and ecological transition strategies.
Although there is still a way to go before aquaponics becomes a widespread practice in Spain and Europe, the combination of technical experimentation, cooperative interest and the search for more resilient models suggests that its role will gain importance in the coming years, both as a tool for diversification in the countryside and as a sustainable production option near cities.
