Spirulina production

Why spirulina?

The local production of nutrient-rich foodstuffs is undoubtedly a sustainable way to lead the fight against malnutrition. The dietary supplement is also in need of political will.

On one aspect of malnutrition, all the experts agree:  malnutrition in the world is not inevitable. It is not the quantities of food produced which are the problem. No, it is the lack of access to a varied diet, and to affordable food prices.

Our field trials have shown that a child suffering from mild to moderate malnutrition can recover with a daily dose of 1 to 3 grams of spirulina over a period of four to six weeks.

One solution proffered to overcome malnutrition is to add micronutrients directly into certain foodstuffs. Whilst this is perfectly justified during emergencies, it is by no means a sustainable solution because of its dependence on imported pharmaceutical and chemical products. This practice is followed by several organisations –including UNICEF – which provide access to supplementary foods such as enriched flours and therapeutic milk. Such imported products are clearly useful at times of food crisis, but they make communities dependent and in no way empower the emergence of local initiatives.

The advantages of spirulina

  • It’s effective: a daily dose of 1 to 3 grams of spirulina, for four to six weeks, will cure a malnourished child
  • It’s local and sustainable: this is a dietary supplement which is grown, sold and consumed locally
  • It means autonomy: spirulina farms, having achieved viability and autonomy, actually create revenue streams for the local community
  • It’s low threshold, using local resources, with low start-up investment
  • It’s high yields, producing 5 to 6 grams of dry spirulina a day, per m²
  • It’s tidy,space-saving and it fits: given the quantity of protein produced, it requires very little space – 15 times less than sugar cane, 20 times less than soya and 250 times less than rice
  • It’s frugal, needing very little water – three to four times less than soya, five times less than maize, and 40 times less than beef
  • It’s business for women: with proper training and capacity building, decentralised production, and processing and sales being suitable for small businesses
  • It’s handy: conservation, storage and distribution are straightforward.

Think global, grow local

The tragic consequences of malnutrition, and the importance of micronutrients in the growth of children aged five years and under, are abundantly clear. They should – should they not? – unfold into an enormous research effort, on a global scale, to deliver new tools for local food production, or to improve the nutritional quality of available food.

In this regard, Antenna has studied, developed and tested the local production of spirulina in developing countries, with all the more commitment because while it is mass-produced for the Western consumer market, small-scale production for the poorest of the poor still remains a marginal economic activity. The transfer of knowledge and technology for local spirulina production is one that offers great, indeed excellent, potential in the fight against chronic malnutrition.

As a result, Antenna has taken the conscious decision to link  awareness-raising and the prevention of infant malnutrition, on the one hand,  with local production and consumption of spirulina, on the other. As a product which is nutritionally rich, light to handle and locally grown, it is a fitting addition to the local staple diet.

Having built our case that this approach to spirulina is both feasible and important, we are now seeking to promote local production and, if possible, to integrate it into the notion – and practice – of nutritional gardening. A country-specific strategy is called for, given the need to harmonise various approaches to local food security. Equally vital is the recognition that to mobilise the full potential of spirulina depends too, on accompanying nutritional information and education. To begin with, it is essential to increase awareness of the real implications of malnutrition.

A supplement to other nutrition strategies

Spirulina is entirely complementary to other strategies to combat malnutrition, such as awareness-raising for mothers, dietary advice, enriched flour or even therapeutic milks. It is their natural partner in the long-term prevention of chronic malnutrition, whereas other solutions are focused in particular on acute malnutrition.

As far as ready-to-use therapeutic foodstuffs are concerned (the best-known is ‘Plumpy’Nut), they do have a certain interest for acute malnutrition (when there are no medical complications), and in emergencies. That said, however, outside such critical circumstances, it is important to cure chronic malnutrition by other, more sustainable, means – notably to avoid the risk of excessive dependence on the part of the communities concerned. In the long term, it is more important to enable local communities to build their own capacities and to meet their own food needs from their own local resources.

Ultimately, spirulina needs to be seen as a meal ingredient that allows dishes to be served which tackle malnutrition; as such, it is complementary to other approaches. Its key asset – that of local production – is essential to its adoption by the community in the long term.

Sustainable economic activity

Spirulina cultivation is also a way for the poorest of the poor to create a sustainable economic activity. It is here – in promoting the development of local communities – that spirulina stands out clearly from the ready-to-use dietary supplements that are imported and distributed by certain large international organisations. Local production means that there is a local supply, separate from the broader market, and from international policies. In addition, money invested in local spirulina production is spent in the domestic economy of the country in question. After all, to spend perhaps less, but solely feeding the revenue streams of multinational corporations, is to make merely a short-term, and illusory, saving.

Read our full report: “A sustainable response to malnutrition: the local production of spirulina”

Produceing spirulina

Thanks to a full 20 years of experience in the field as Antenna, we have developed the tools and training processes needed for the production of this remarkable dietary supplement in developing countries. Recommended by the FAO [A review on culture, production and use of spirulina as food for humans and feeds for domestic animals and fish, FAO, 2008], the local production of spirulina gives communities access to a local and sustainable source. Antenna can enable the poorest families to cure and prevent nutritional deficiencies, which afflict children in particular.

Local production of spirulina is a tool for development

Spirulina cultivation has a humanitarian aspect because it brings with it a growing awareness by stakeholders of the causes of malnutrition and its own role in enhancing the nutritional state of a country.

Cultivating spirulina in situ optimises its availability for the local community and is more appealing than an export product, thereby becoming more acceptable for consumption.

By deciding to grow their own spirulina, developing countries can gradually integrate it into eating patterns. This route will allow it to become not only an excellent weapon in the fight against malnutrition but also a real tool for development.

It is therefore not surprising that local communities are highly motivated to be involved on a commercial basis. This can be done by establishing an efficient network for distribution and communication, as well as a targeted education strategy with the local community on the nutritional qualities of spirulina.

Production techniques

We have conducted research on spirulina since 1992. We have benefited from the assistance of engineers and scientists, notably Jean-Paul Jourdan, in developing a method of growing spirulina at the local level, simply and effectively. This makes use of a production system in tanks and basins. The simple method of cultivating spirulina is especially suited to developing countries and to the realities of hot and desert climates.

Our support for pilot production sites in tanks in developing countries underscores an innovation that is appropriate to the wide-scale dissemination of a crop which is never damaged by insects or plant disease. For our partners, we develop informational materials about the usefulness of spirulina; we provide a stock of selected spirulina cultivars; and we outline appropriate methods of cultivation, harvesting and consumption. Growth tanks can be either rectangular or round, with a depth of 20 cm, and constructed with simple, low-cost materials.

  • On an annual basis, each m² cultivated can supply a cure for 20 children with deficiencies.
  • 1 m² tank => production of 6 g/ day => 2 kg of dried spirulina a year.
  • The cure for a malnourished child lasts for six to eight weeks, using 2 g of spirulina a day, thus requiring => 100 g of dried spirulina
  • The construction of a tank and accessories costs between EUR 100 and EUR 200 per m² (depending on size).
  • Production of spirulina costs between EUR 15 and EUR 20 per kg.

The required growth medium is a simple one, and can be made from fertilisers available in any large town. Contrary to some expectations, the volume of water required for producing spirulina is much less than for any other traditional type of agricultural production. With its high productivity and the small amounts of spirulina required per person, the growing areas required are also very small.

Finally, many climates welcome spirulina production all year long. Further, since it is eaten locally, there is no need to conserve it. Indeed, fresh spirulina can be eaten directly without any processing or cooking, and thus without any additional use of energy.

There are varying scales of production, from household-level ‘micro-production’ to semi-industrial plants. At the level of micro-enterprise plants on a small and medium scale (producing between 50 and 3,000 grams of dried spirulina a day), all materials and most of the equipment needed is normally available locally. The main inputs required are conventional agricultural fertilisers, water and – optionally – electricity. Another input is soda, or bicarbonate of soda, which are both, in general, easy to source. They can also be replaced by wood ash.

Harvesting can be done on a daily basis, and starts very soon after sowing the tanks. Generally, the first harvest is within a month and half of starting operations. Harvesting is simple, through a simple filtration of the growth medium. The filtered mass is then dried for the rest of the day and processed at the end of the afternoon.

When the dried mass has been crushed to powder, it can be eaten immediately, or added to traditional foodstuffs. Given its ease of use, spirulina is accepted even more by women when they witness for themselves how the health of their children improves. With adequate packing, spirulina or spirulina-enriched products can be stored for long periods. This means that these high-value products can be stored and sold on local markets.

Safety in production and protection against contamination

Given that spirulina is a photosynthetic micro-organism which grows in an aquatic environment, it avoids any problems of soil quality, parasites or plant disease.

The fact that it grows in completely mineral growth media which are very alkaline (classically pH 10, rising to pH > 11), spirulina is practically immune to contamination by other organisms. This gives it the advantage that it can be grown with essentially no risk, even in low-tech situations and in tropical climates.

In fact, the only stage in the production process when great care is called for in terms of the final product, if the product is to be shipped far or kept for longer than a few hours, is at the time of drying. Once the spirulina has been thoroughly dried, it can be consumed immediately.

Circular tank


  • Enhanced crop yield: the spirulina blend is properly mixed, and given optimal exposure to the light.
  • Improved maintenance of the tank reduces overall production costs: the culture is constantly cleaned and its quality allows cultivation for a longer period (over one year) => reduced cleaning requirements and the number of tank drains.
  • Energy costs are reduced: the power required to start up the cleaner-mixer system is 10 times lower than in a conventional tank.
  • The cleanliness of cultivation conditions is improved: the system removes surface froth, thereby avoiding fermentation and encouraging gaseous exchanges of the growth medium with the air. Greater cleanliness of the tank area improves the overall look of the production site (making it more attractive for visitors).

How it works

  • The unit has four arms spanning the diameter of the tank, mounted on a central pedestal column, allowing it to rotate fully. Where the wind is steady (average: 10km/h) without being too violent (near the sea, for example), wind propulsion can be considered. In the absence of wind, it is possible to run the system with a high torque gear motor mounted on the central axis.
  • Long-arm surface scraper: this skims the surface of the tanks and pushes the excess supernate (of foam and rubbish) into a recipient which can be easily emptied.
  • Short-arm scraper for tank bottom: fixed below each arm, these scrapers clean the tank bottom, pushing the spirulina crop into a collection vessel, which should be emptied daily.

Practical guide to spirulina cultivation

Grow your own spirulina (in French), Jean-Paul Jourdan and Antenna Technologies, 2006 (updated 2013)

Artisanal and solidarity spirulina cultivation news in brief, Spiruline France, Jean-Paul Jourdan