Algae farms are places where algae is grown for commercial use. People engaged in algae farming are said to be involved in algaculture. Algaculture can involve growing many different species of algae.
Most types of algae that are commercially grown are microalgae. These are sometimes referred to as phytoplankto, microphytes, and planktonic algae. Some of the larger algae species, also known as macroalgae, include seaweed and also have commercial uses.
However, their larger size and the more precise growing conditions for macroalgae make them more challenging to cultivate in a controlled environment.
Some of the uses of commercial algae grown on algae farms includes food coloring, fertilizer, bioplastics, chemical feed, medicines, pollution control, and fuel. Some varieties are also grown as food for humans or as nutritional supplements.
Most algae farms grow only one type of algae. This is known as monoculture. Algae farmers choose the variety they are going to grow and take great care to keep their supply pure, as it is easy for other species to get into an algae culture and then come to dominate it.
Pure cultures of one type of algae are the most valuable for commercial purposes and for research.
When mixed algae species are grown together, it is usually as food for other sea creatures, such as larval mollusks. This is a relatively low maintenance way to feed commercially farmed seafood.
All that is required is a filter to remove algae that is too large for seafood to eat, and a day or so in a greenhouse pool or outside so the algae gets the necessary nutrients to make it healthy for the seafood it will feed.
When cultivating algae on algae farms, there are some basic requirements for producing a good stock, regardless of the species. Light, water, and minerals are all important ingredients in producing healthy algae. So is carbon dioxide. This combination produces the energy algae needs to grow.
Algae can sometimes be grown without sunlight if sugar is used to directly feed it. In these cases, carbon dioxide is also not required to grow the algae. Most algae farmers prefer the light method.
Algae could be used as a source of fuel.
The temperature of the water in which the algae is grown is also important. Each species of algae has its own particular temperature range in which it does best. However, the optimum temperature range for algae of any kind is between 25 and 35 degrees C.
When it comes to harvesting algae, several different methods can be used. The most common are flocculation, centrifugation, and microscreening. Flocculation is an expensive method of harvesting algae that only large algae farms can usually afford.
It uses the powdered shells of crustaceans to interrupt the carbon dioxide supply of the algae, which causes algae to float to the surface of the water where it can be skimmed.
Centrifugation spins the water containing the algae in a centrifuge to separate the algae from the water and is a medium-cost method of harvesting due to the cost of the centrifuge. Finally, microscreening simply uses a fine mesh screen to sift the algae directly out of the water.
From harvesting, the algae is then dried and sent to the various companies around the world that have ordered it for the many purposes it can serve.
Algae farming promotes clean technology. It is a ready source of food for both animals and humans. It can be used as nutritional supplements almost as-is. It has the ability to clean up pollution from the water and the air.
Most of all, it provides a clean source of fuel for transportation and heating that produces no greenhouse gasses or other pollution when it's used. It's non-toxic and safe to grow and harvest. It is also an extremely renewable resource.
Algae has been around for millions of years and will probably be here as long as there is a habitable earth. We can't run out of it. This makes algae farms part of the green technology of the future.
Image Credit: photos.com
Further Reading: Experience with Algal Farms, AlgaePARC, ISU's Algae Farm, MIT Tech Review
Algae Farm - Run Time: 8.16mins