Showing posts with label 2009. Show all posts
Showing posts with label 2009. Show all posts

09 April 2011

Aquaponics Technology

Harmonising Nature and Technology with Aquaponics

 

Born from the abstract philosophy of ecocentric ideals, aquaponics has emerged at the very frontier of agricultural technology. Yet, many years after the modern concept was first realised it has yet to receive the commercial recognition that might unlock its true potential, writes Adam Anson, reporting for TheFishSite.
By definition, aquaponics is the symbiotic cultivation of plants and aquatic animals in a recirculating environment. What it could offers to the world of aquaculture and agriculture is hugely promising, yet its name is rarely uttered within the food sector.

Advocates of aquaponics will say that a well balanced system could eradicate the costs of feed, supplements, continuous employment and waste management. In return, providing a variety of high quality, natural food products in high yielding quantities, but the reality of the technology in practise today adheres to few of these promises.

Modern aquaponic systems usually take place within greenhouses in order to maximise conditions. Water from the fish tank is filtered and recirculated by the biological methods of the plant. Ammonia, nitrates, nitrites, and phosphorus are stripped away and then the freshly cleansed water is recirculated back into the fish tanks. In return, nutrients generated from fish manure, algae, and decomposing fish feed - that would be toxic to the fish - serve as liquid fertilizer to hydroponically grown plants.

Essentially what these systems create is a self sustaining renewable system that does not require fertilisers for the plants, or fresh water for the aquatic animals. Current systems still require the addition of fresh salt and water replacement for evaporation and plant uptake, but in principle even these inputs could be eliminated.

Practical Uses

 

The use of aquaponics is not a new idea. Some people point back to ancient Egypt when tracing its roots, but a modern view of aquaculture stems from the permaculture movement that began as an agro-ecological design theory in the 1970's.
Developed by Australians Bill Mollison and David Holmgren, the idea was used to create stable agricultural systems. This was a result of their perception of a rapidly growing use of destructive industrial-agricultural methods. Since then, aquaponics has become a movement in its own right, serving as a model of sustainable food production for both land-based and aquatic organisms.

A recent publication by the National Sustainable Agriculture Information Service (ATTRA) took a look at present day aquaponic systems in the US and current research into the production methods. According to the publication, Aquaponics - Integration of Hydroponics with Aquaculture, farmers are beginning to take an increasing interest in aquaponics due to the low input and waste management costs and also the green credentials that they provide.

For all its potential aquaponics must currently utilise complex technology and the skilled ability of workers to simultaneously monitor, manage and market the different types of agricultural products it creates. However, recent innovations have transformed aquaponic technology into a viable system of food production, claims the report. These systems can be highly successful, but they still require special considerations. Knowledge of both hydroponics and aquaculture are currently essential to the management of an efficient system.

Not all plants are adapted to strive in aquaponic greenhouses. Similarly, nor are all aquatic creatures suited to aquaculture systems. Furthermore, those plants and fish often require specific conditions to strive. pH, temperature, oxygen levels, feed are just some of the aspects that must be managed for optimum growth. It is the bringing together of these right conditions that makes aquaponics so difficult.

On top of that, managers must also harmonise the stocking densities of the chosen plants and animals. "Matching the volume of fish tank water to volume of hydroponic media is known as component ratio", explain the report. "Early aquaponics systems were based on a ratio of 1:1, but 1:2 is now common and tank: bed ratios as high as 1:4 are employed. The variation in range depends on type of hydroponic system (gravel vs. raft), fish species, fish density, feeding rate and plant species,"

However, if the basic set up of the system is correct, yields can more than compensate for the hard work. Not only will the input cost be minimised, but also the value of the product will be high. Products should be well managed and healthy, containing no artificial chemicals, or hormones and having no adverse effect upon the environment.

The products can then be marketed as organic and in return demand a greater price at market. Unfortunately, although organic aquaculture has a valued market in many countries, there has been no global consensus on its definition and a US Department of Agriculture accredited organic label has remained entirely allusive. For this reason, a movement towards organic aquaculture has been severely hampered.

Not So Radical Thinking

 

In many ways, the complexity of aquaponics requires an understanding of all life. Farmers must engineer a whole ecosystem that caters for the need of all the plants and animals that live within it. And yet, essentially, aquaponics lets nature do what it does best by allowing it to deal with the complex underworld of interactions, soil structures and micro-organisms that we really do not understand. Rather than attempt to bend nature to the whim of human knowledge, it realigns our knowledge on its path.

Aquaponics should not be judged and seen merely through the green-tinted lenses of eco-friendly eyes, it should be mutually acknowledged for the advantages it can provide on economic, health and market grounds. Not only does it harmonise yield products, but it also fuses natural processes with highly advanced technological ones to derive the best of both.

Unfortunately, with the rapid advancement of huge machines and intensive monoculture operations behind us, it can be difficult to look again and see a natural agricultural process take its place and be just as efficient. But time and again, the problems that intensive operations encounter have proved difficult to overcome with manmade contraptions. Nature already has the answers to most of our problems, it is merely learning to see and listen to them that often hinders our advancement. 

credit to:
http://www.thefishsite.com/articles/570/harmonising-nature-and-technology-with-aquaponics

14 March 2011

Aquaponics in Space

Two years ago, a NASA Engineering Design Challenge asked students to think about the possibility of growing plants on the moon and then to design, build and test lunar plant growth chambers. On future long-duration missions on the moon, fresh-grown plants could be used to supplement meals.

A group of high school students from New Jersey not only came up with a unique way to grow plants, but their plant growth chamber also includes an idea for providing a source of protein for lunar astronauts. The project by students at the Atlantic County Institute of Technology in Mays Landing, N.J., uses aquaponics -- plants and fish in the same environment.

Aquaponics combines aquaculture (raising fish) with hydroponics (growing plants without soil). The system designed by the New Jersey students combines bluegill fish and plants in the same tank. The fish live in the water in the bottom of the tank. The plants grow in the top half of the tank.

The seedlings are grown in rock wool, which is a type of mineral wool used in hydroponics. The seedlings are then suspended in a plastic pipe in the top half of the tank. The water is pumped from the bottom of the tank through the pipe, then back into the tank. The roots of the plants are exposed to the water stream as it flows through the pipe. As the plants absorb the nutrients in the water, they also filter it.

"The system is a symbiotic relationship between the plant and bluegill fish," explained the students' science teacher, Melissa Hannan. "The fish provide nitrogen and phosphate for the plants, while the plants provide beneficial bacteria to convert ammonia."

A large aquarium tank with fish in the bottom and plants in the top
 
The system designed by a group of New Jersey students is an aquaponic system, which combines fish and plants in the same environment. Image Credit: Atlantic County Institute of Technology
Plants receive light from light-emitting diodes, or LEDs, under the wooden canopy on top of the tank. The lights are powered by solar panels. Reflective material on the sides and back of the tank enhances the solar-powered lighting, Hannan said.

Students researched bluegill fish, different mediums to grow seeds, and the chemical conversions taking place in the tank. They used three-dimensional design software to create a computer model of their tank design before building it.

They also experimented with the angle of the pipe and the water pressure to achieve the best results. "Our final product is quite different from our original product," Hannan said. "It was a lot of trial and error, which is exactly what science is."

Bluegill fish were chosen because of their small size and the constraints of the 45-gallon tank. However, Hannan said students are testing the same concept with freshwater bass in a 12,000-gallon tank in the school's greenhouse. In the small tank, students grew cinnamon basil seeds that had been flown on the STS-118 space shuttle mission in 2007 and distributed as part of the design challenge. In the larger greenhouse model, they are experimenting with growing herbs and lettuces.

Atlantic County Institute of Technology students Alex, Jack and Marco received a second-place medal for their project in the 2009 New Jersey SkillsUSA technology competition. Image Credit: Atlantic County Institute of Technology
"They thought it (aquaponics) would be a good idea for the astronauts on the moon because it's a self-contained system to provide protein and vegetation," Hannan said.

Students received a second-place medal for the project in the New Jersey SkillsUSA technology competition earlier this year. Hannan said judges were impressed with the construction of the system.

"What they (students) are really taking with them is hands-on experience," Hannan said. "They're learning what it's like to start a project, hit some problems and actually solve the problem, solve the issues, and refine your system and make it (work)."

The Engineering Design Challenge: Lunar Plant Growth Chamber project supports NASA's goal of attracting and retaining students in science, technology, engineering and mathematics disciplines.

link: http://www.nasa.gov/audience/foreducators/9-12/features/aquaponics.html

09 March 2011

Aquaponics DVD

Aquaponics Made Easy (2009) DVD
by Murray Hallam

Grow fish and vegetables together in your own backyard the easy way. Whether you want to build your own system from bath tubs or assemble a ready-made kit, Murray Hallam will guide you through every step, so you can enjoy fresh fish and organic vegetables at your place.

If you’re worried about using commercially made fish pellets, Murray will show you how to grow your own fish food – the natural way.

Everything you need to know to get started in your Aquaponics adventure is packed into this educational DVD.

Over 90 minutes of quality information:

* Assembling a kit system

* Grow Beds, Tanks, Gravel Media explained

* Flood and Drain, Auto Siphons

* Fish Aeration, pumps, filtration, backup systems

* Growing plants successfully

* The Nitrogen Cycle, Fishless Cycling

* Testing your Water

* Maintaining a balanced system

* Choosing suitable fish for Aquaponics

* Batching your fish for endless food

* Dealing with pests

* Feeding your fish – Growing your own fish food

* Building your own Bathtub Aquaponics system

* Solar powered systems

* Essential checklist summary