Organic Spirulina Farming – Cultivation, Growing Guide

Introduction to Organic Spirulina Farming, Production

Spirulina (Arthrospira platensis) is a naturally occurring blue-green micro-algae which grows in warm water alkaline lakes and it is used as a nutritional supplement. It is a type of blue-green algae that’s loaded with nutrition such as protein, antioxidants, and numerous vitamins and minerals. Spirulina is a simple organism that grows easily in freshwater as well as saltwater. Though, because algae can absorb toxins found in the environment, some people opt to grow their Spirulina at home in safe and controlled conditions.

A Step by Step Guide to Organic Farming of Spirulina and Growing Practices

Spirulina grows and thrives in warm water alkaline ponds and rivers. A potent nutrient-dense whole food, it is over 60 to 70% protein, and is a complete protein, supplying all 8 essential amino acids. You can produce Spirulina in any closed conditions with the availability of water. The optimum temperature for this Spirulina cultivation is 30 to 35°C. The only thing that you need for this is a good amount of Sunlight. In concrete tanks, plastic tanks in circular or square ponds, you can produce Spirulina.

Organic Spirulina cultivation is a low investment and high-income farming. The Spirulina cultivation cost is low and the profits that can be obtained are quite high. Finding buyers for the produce is also easy given there isn’t much availability of it in the market and the produce can be sold for almost as high as Rs 1000/kg. The cost of organic Spirulina cultivation depends on the cost of raw materials, local labor, packaging, and logistics and is dependent on the local market. It may vary from place to place.

Spirulina thrives on inorganic matter and requires little “organic” nutrients, so technically, there is no such thing as organic Spirulina. The accurate definition of “organic Spirulina” would be Spirulina that was grown on natural minerals, as opposed to chemical minerals. In Spirulina cultivation, there are various methods to feed Spirulina with either chemical or natural minerals. Confusion with organic Spirulina and Non-organic Spirulina is that many organic certification bodies still don’t have a clear policy regarding the certification of Spirulina as organic.

Guide to Organic Farming of Spirulina.
Guide to Organic Farming of Spirulina

Advantages of Organic Spirulina Farming

  • Spirulina can be produced locally and so it has social as well as economic benefits
  • Cheap to produce
  • Uses simple technology and locally available materials
  • Requires less water to grow than vegetables
  • Very easy to digest
  • Spirulina is a potent source of nutrients. It contains a powerful plant-based protein called phycocyanin.    This has antioxidant, pain-relief, anti-inflammatory, and brain-protective properties.

Requirements for Organic Spirulina Farming

Spirulina cultivated for commercial and large-scale production has to be done in regions with proper climatic conditions. Tropical and sub-tropical regions are well-suited places for Spirulina growing. It requires sunshine throughout the year. The growth rate and production of Spirulina mainly depend on various factors such as wind, rain, temperature fluctuation, and solar radiation.

For a high production with high protein content, temperature levels between 30° to 35°C is ideal. Spirulina can survive in temperature levels between 22° to 38°C but the protein content and color will be affected. Bleaching of cultures takes place when temperature levels are above 35°C and Spirulina cannot survive in temperatures less than 20°C.

Spirulina grows in solutions of specific minerals with the right chemical balance and requires a pH level of 8 to 11. There are different recipes for this, depending on the budget available and the growing conditions. It needs a minimum of 20°C to grow substantially, though a temperature level of 35-37°C is most effective. A good amount of sunlight is useful for Spirulina farming if the culture has a reasonable temperature and concentration. At very low-temperature levels, low concentration of culture, or a culture that is struggling to grow.

The intensity of light plays an important role in Spirulina growth. In Spirulina farming, light has a direct effect on protein content, growth rate, and pigment synthesis. The light intensity between 20 to 30 K lux is found to be ideal for Spirulina cultivation. Spirulina yielded the highest protein content under the blue light. Yellow, white, red, and green light are the next levels of the protein generated.

Water Quality in Organic Spirulina farming

In commercial Spirulina farming, it is mainly required to recreate the close culture medium in which blue-green algae grows naturally. Water is the main source medium for growing Spirulina. It has all the necessary sources of nutrition for the healthy growth of Spirulina. Then, the ideal water quality must be maintained throughout the micro-algae mass production by providing a controlled salt solution in the water. The ideal pH value culture medium must be between 8 to 11 ranges and the water level in tanks or pits should be controlled. The water level is very important for the photosynthesis process to take place in all organisms. The deeper the water level, the sunlight penetration will be reduced, which will affect algae development. A minimum shallow level of about 20 cm is the ideal water level height.

How to Start an Organic Spirulina Farming

First, you have to select a proper tank either cement or plastic for this Spirulina cultivation. You have to procure the mother’s spelling of mother cultivators and then shift it to the water tanks. And, make sure that the container with Spirulina gets enough sunshine. With proper sunshine, Spirulina will take a minimum of about 10 to 15 days to develop. In the winter season, it will take some extra days to develop. Make sure that there is no contamination during the process in the winter season. This is how you have to start organic Spirulina cultivation in cement or plastic water tanks.

Construct a Container for an Organic Spirulina Farming or Production

Building any pond cement tank or plastic tank is important for the Spirulina cultivation. You can grow Spirulina in square or rectangular ponds or even you can grow it in circular ponds that have a large area and minimum depth. Then, you have to protect it from contamination you should grow it always in a closed container. You must create rectangular tanks with a depth not exceeding 100 cm to achieve better performance spiral inside. This is the best Spirulina cultivation house.

You should have the only freshwater for this organic Spirulina cultivation and never add saltwater has blue-green algae might not grow saltwater. This will grow daily and collect that once in a while with the cloth so that you do not contaminate it. As you remove blue-green algae daily there rises the need for adding freshwater and then you have to add water once in a while with the pump that you have. Also, you should add fertilizer like sodium bicarbonate to the water tank to help the Spirulina grow quickly.

Organic Nutrients Required for Spirulina Farming

Spirulina produces in a high concentration of organic nutrients may have a higher bacterial count since bacteria thrive on such organic nutrients. This may not be noticeable in the final product if producers take further processing steps like pasteurizing, irradiating, and fumigation, etc.

Nitrogen is an important component of amino acids, the building blocks of protein. It is also a component of many important enzymes that are themselves proteins. Since Spirulina is about 60% protein, it requires a large amount of nitrogen for growth. Some animal fertilizers used to grow organic Spirulina is compost tea and various manures. Risks from high organic fertilizer loading contain potential toxins and disease organisms.

The Process of Organic Spirulina Farming

Spirulina is a type of bacteria called cyanobacterium normally known as blue-green algae. Spirulina produces energy from sunlight through the photosynthesis process. The water has to have the right pH level and alkaline by adding required salts at the required rate. Once the water has a standard micronutrient composition, then the pond is ready for Spirulina seeding. For uniform growth, 30 grams of dry Spirulina is added for every 10 liters of water. Also, concentrated live Spirulina culture can be used as seeding the pond. In commercial farming, one pond is exclusively kept for rearing Spirulina as seed. Then, this will reduce the regular purchase and the farm becomes self-sustain and also can sell live Spirulina seed to other farmers.

The algae bacterium starts to double in biomass within 3 to 5 days. Organic farmers have to continually check the nutrient content value and adding fresh water at regular periods for good production and top crop yields. The matured Spirulina changes color from light to dark green. The concentration of algae and color of the algae is the deciding factor for when Spirulina must be harvested. The water level in the pond maintained at 20 to 30 cm and 25 cm is the ideal water level height. As most of the ponds are open the evaporation of water will affect the Spirulina cultivation. Especially during the summer season, on an average thrice in a month, freshwater is released into the ponds to maintain consistent (25 cm) water level height throughout the cultivation.

Contamination of culture medium will have a direct effect on the organic Spirulina production. It can happen by insect breeding, foreign algae, or through chemical contaminants. Any amount of chlorine present in the water will kill the algae development. This will lead to a complete loss in the production of organic Spirulina. The larva of mosquitoes and insects will feed on algae leading to about an overall 10% decrease in production. At the time of Spirulina harvesting, the existence of larva or pupae will contaminate the Spirulina quality and yield. All extraneous materials can be removed from the culture medium with the help of a fine wire mesh frame.

Production or Extraction Process of Spirulina

The production of Spirulina mainly consists of four processes,

1. Culture – Initially, Spirulina is cultured under the same condition as its original habitat, salt-water lakes, in the subtropical area. Then, alkaline culture solution with nutrition is poured into a wide shallow culture pond, which is stirred by gentle streams. This allows Spirulina to efficiently carry out the photosynthesis process and to multiply.

2. Filtration – In this process multiplied Spirulina is in the form of algae. Then, it is separated from the culture solution through filtration.

3. Washing and Dehydration – It is separated from the culture medium. Condensed Spirulina is placed on a vacuum dehydration filter. Then, repeatedly washed with clean water and dehydrated.

4. Drying – The dehydrated Spirulina is instantaneously dried with a spray dryer and then made into a fine powder.

When and How to Harvest Spirulina

The algae concentration in the tank is the deciding factor for Spirulina harvesting. As mentioned above, 0.5g/L is the ideal concentration and this is usually achieved 10 days after the seeding process is complete. The algae are collected and then passed through a simple filter which drains out the water. When the water is heavy with Spirulina, it is scooped up and then passed through a set of filters. The Spirulina biomass is collected in the finest filter, where it is drained and then cleansed with water.

The cleansing process is finished when the water seeping through the filter stays fully transparent. This is one of the most efficient organic Spirulina cultivation methods. After the filtration method, the algae are pressed upon by large weights to further reduce the moisture content. Then, the product is now pretty dry and can be sent for further processing which is done in machines. It involves processing the algae through machines that are used for making noodles and thin strips of algae are made for the ease of further processing. The noodle shaped algae are kept on a clean cloth and then dried under the sun. It is allowed to dry for a couple of hours under the hot sun. It ensures that the algae have completely dried now and is ready for the next procedure. The next stage involves grounding of the algae in a similar way flour is produced. The Spirulina is grounded and then made into a powder which is then further tested. The Spirulina testing is done in laboratories where they check the edibility of the product and mark it safe for consumption or not.

Challenges in Spirulina Farming and Solutions

There are certain challenges faced during the cultivation of organic Spirulina. Be careful with the temperature of the water and start Spirulina cultivation with a clean tank to avoid any discoloration of the medium. Allow enough sunlight or the cultivation might turn pale and Spirulina growth will stop.

Sometimes there could be foam formation in which case ash water can be added to reduce the foaming effect which will take a hit to the produce. Urea is important in the cultivation and if a gelatin type substance starts forming, it can make the mixing almost impossible. In that case, more urea must be added to the medium. Then, do not allow the mixture to reach a stage where they might smell like ammonia. It is not good for the cultivation and more water should be added. Keep the nutrient check on the scale particularly if the mixture starts turning lime green color. There could be problems particularly when you are starting new and the harvesting should be done at the right time.

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pH imbalance – After building your medium in the tank and adding in the live Spirulina culture, it’ll look fairly thin and watery. But if you find that Spirulina doesn’t start to thicken over a couple of weeks, the first thing you should check is the pH using pH strips.

Spirulina’s comfortable pH is about 10. Generally, the nutrient solution should be enough to bring the pH level of the filtered water up from around 8 to 10, but problems can still arise. If you find that the pH level is too low even after adding the nutrient solution, try adding a little bit of baking soda, which is made up of sodium bicarbonate. If the pH level gets too high (up to 11), add some vinegar to your solution, which contains acetic acid. Just add a little at first, and re-check the pH level.

Nutrient imbalance – If you notice that Spirulina culture is producing a lot of bubbles, then turn off the air pump. If you weren’t using an air pump, it’s probably because of an imbalance in nutrient proportions. Then, add some water and a little bit of baking soda. If the bubbles continue after a couple of hours, add more culture medium like water and nutrient mixture.

Commonly Asked Questions about Organic Spirulina Farming

How long does it take to grow Spirulina?

It should take about 3-6 weeks for Spirulina to grow after adding the culture to the medium. You’ll know it’s ready to harvest when it’s dark green color and looks thick in the tank. You can verify that it’s ready by making sure the pH level remains around 10 for 24 hours.

Is fresh Spirulina better than dried/powdered?

Generally, fruits and vegetables are always better and healthier when eaten fresh than in a powdered or dehydrated form, and Spirulina is no exception. So, fresh Spirulina is indeed better and also has more health benefits than powdered Spirulina.

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  1. Your article is very helpful. We want to start a spirulina cultivation very soon. Please provide necessary information / instructions to us. Thank you.

  2. I am very much interested in organic spirulina farming at my field as commercial crop.please guide me with all information n give information about complete set-up of tank, machinary,moter, paddle etc….etc.provide mobile no.of those who will make complete spirulina farming set-up…


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