Spirulina are blue-green microorganisms that grow both in the ocean and in fresh water. While often referred to as algae, they are not related to the algae species. However, they can engage in photosynthesis since they are autotrophs. Spirulina is very healthy, often serving as a food source. As a dietary supplement, spirulina can come in tablet, flake or powder form. Some farmers feed their animals spirulina to cut down on food costs.
Spirulina is also referred to as arthospira. These microorganisms thrive in tropical and subtropical lakes with high pH. If the arthrospira are grown in tanks, the water must be at least 84 degrees Fahrenheit with high pH.
Most farmers grow spirulina in open-channel, shallow raceway ponds and use paddle-wheels to move the water. The motors that pump fresh water into the spirulina ponds can use solar cells to minimize energy consumption and waste. These bacteria can double their biomass every two to five days. Farmers can easily convert unfertile land into spirulina-growing ponds as these ponds can operate anywhere. Growers must continually add clean, fresh water and nutrients to keep the spirulina thriving. Since spirulina consume carbon dioxide faster than the gas can naturally penetrate the water, farmers must add sodium bicarbonate to the water. Spirulina need nitrogen, potassium and iron the most, so farmers must add these nutrients to the water.
Spirulina cultures change rapidly if not cared for properly. Cultures can grow quickly or perish in under a few hours. Spirulina ponds are easily contaminated by toxic microorganisms, and farmers must carefully control environmental conditions. Therefore, spirulina must grow in man-made ponds. The water must be kept between 84 and 95 degrees Fahrenheit at all times.
The spirulina is harvested with filters that first remove pond debris then scoop up the spirulina. The nutrient-laden water is then returned to the ponds. What's left for the farmers is a green dough that must be flash-dried for three seconds then packaged. Spirulina has a very high amount of protein, comprising 55 to 77 percent of its weight when dried. Since protein is often one of the most expensive nutrients to purchase, spirulina production can help impoverished regions meet their protein intake demands. Manufacturers also mix spirulina in milk or juice to create energy drinks.
Farmers can pump the leftover nutrient-rich water to farmlands to minimize fertilizing costs. Spirulina oxygenate the water, which helps replenish oxygen in ponds. But the large number of nutrients can also encourage harmful algae growth.