Posts Tagged ‘ water ’

Fresh water solution not a pipe dream

Victorian company F CUBED says it may have found the solution to the world’s water woes with the launch of a new modular, direct solar-powered desalination system branded as Carocell. The system, which has been 6 years in the making, produces potable water from seawater, groundwater, contaminated and polluted water.

Carocell units can be ground or roof-mounted and emit zero greenhouse gas emissions. The system uses no chemicals, filters or electronics and also enables rainfall to be captured and harvested. Disease-causing pathogens and heavy metals are removed during the purification process and minerals and salts are separated and can be reused as part of the supply chain.

“We have created the most cost-effective and highly efficient solar desalination system currently available on the world market,” said Stuart Eastaugh, F CUBED’s National Sales Manager.

“Independent tests reveal Carocell to be almost twice as efficient as comparable systems (65%-80% water yield per megajoule of energy when compared to 30-40%*) and significantly cheaper to purchase and install,” he said.

Carocell units are manufactured in different sizes and multiple panels can be connected together in order to produce large quantities of distilled water suitable for a small town or major commercial operation use, or a single panel can generate enough water for an average family’s use.

“As water demand increases, the number of panels can also be increased or decommissioned when no longer required. Most of Carocell’s components can then be refurbished or recycled, providing another level of sustainability to an already clean energy product,” he said.

The components, including custom designed steel framework manufactured from durable OneSteel Galvatube precision tubing, have a lifespan of 20 years or more for each system – even in the most challenging conditions, according to a company spokesman.

OneSteel’s Product Manager, George Kourtesis said that the strength and anti-corrosion properties of OneSteel’s Galvatube pre-galvanised tubing were critical factors when it came to F CUBED sourcing steel components for the construction of the Carocell modules.

“At the time of Carocell’s development we were working with F CUBED on a range of projects. The F CUBED team chose our Galvatube steel tubing based on the fact it is galvanised internally and externally and has been specifically designed for outdoor use where greater protection from corrosion is required,” Mr Kourtesis said.

“Additionally, Galvatube’s structural integrity is second to none. It can withstand the most challenging of environmental conditions, particularly those experienced in situations such as desalination plants or mining site.”

F CUBED said it is experiencing a high level of demand for its Carocell systems, including from governments and organisations wishing to provide safe water to developing countries along with industrial and mining industries, agriculture and horticulture operations, urban usage and as a replacement for bottled water.

“From one hectare of Carocell panels we can produce on average over 55,000 litres of pure, distilled drinking water a day,” Mr Eastaugh said.

“Our system is a combination of high-tech and low-tech processes and follows the same basic principles of the natural water cycle from evaporation and condensation. The system operates on a continuous flow of feed water. As the water moves over the solar collector, a percentage is evaporated to create distilled water and the remaining flow travels out as a brine stream. This brine stream can then be reprocessed, increasing in concentration before being directed to the zero liquid discharge unit.”

The Carocell modular unit retails for AU$362.50 (+ GST and freight).
*Independent tests conducted by world renowned engineering firm, ARUP. Report available on request.

For further information contact:
George Kourtesis,
Product Manager-Precision Tube,
OneSteel Australian Tube Mills
Ph: +61 (0)2 9792-9085
MB: 0448 422 427

Stuart Eastaugh, National Sales Manager,
F CUBED Australia Pty Ltd
Ph: +61 (0)3 8339-0006
MB: 0418 52 8883

Breakthrough technology improves lettuce harvest yields

BiOWiSH™, a breakthrough enzyme technology, has boosted hydroponic lettuce weights by up to 30% at harvest time, according to results of a recent trial. The new technology was adopted during multiple full growing cycles at the Glenorie Hydroponics lettuce farm in New South Wales. The results showed BiOWiSH™ treated lettuce were 17% to 30% heavier at harvest time for red and green butter lettuce varieties, respectively.

BiOWiSH™ is a natural soil ameliorant and water treatment that provides an optimum environment for plant development and growth. Through the action of a proprietary group of enzymes and co-factors, BiOWiSH™ enhances the availability of nutrients, producing healthier, more vibrant and stronger plants.

Joe D’anastasi, owner of Glenorie Hydroponics, said the technology will revolutionise the industry by helping farmers to harvest more regularly.

“I have been in the hydroponics business for 23 years and I haven’t seen anything like it before.”

“We introduced the technology in one of our worst performing greenhouses, to really test it out, but within weeks it became one of our best in terms of plant performance and health.

Not only were the lettuces heavier, they were also thicker and more consistent,” he said.

According to BiOWiSH Technologies Sales and Marketing Manager, Cameron Burgess, the technology also prevents problematic sludge build-up and algae accumulation in irrigation channels by accelerating the breakdown of organic wastes into its final inert compounds.

Mr Burgess added that the potential impacts of the technology on a global scale are huge.

“Food production needs to triple in the next 50 years to feed a rapidly growing global population. It is exciting to think what our technology can do to help address looming food shortages worldwide,” he said.

BiOWiSH Technologies owns exclusive rights to BiOWiSH™. The company has adapted the technology for the hydroponics market by developing a powder product called BiOWiSH™-Crop, which is added to irrigation tanks as part of a hydroponics farm’s nutrient system.

BiOWiSH™-Crop is distributed locally by Accent Hydroponics. To download the complete Glenorie Hydroponics case study, go to the company website.

For further information contact:
Lorenzo Gella,
BiOWiSH Technologies

Issue 110: Feeding Sydney

January/February 2010
Author: Christine Paul

The University of Western Sydney, in association with the UWS Hawkesbury Foundation, recently held its inaugural Hawkesbury Conference where the focus was on challenges that major world population hubs like Sydney face. Against a background of dwindling agricultural land and water supplies, increasing pressure is also being placed on farming systems – what, if any, are the solutions?

Recently, the NSW Government announced the release of 800 hectares of employment land in Western Sydney to create the Western Sydney Employment Area with a capacity for up to 16,500 jobs and expected to eventually accommodate some 40,000 workers. The initiative is touted as a great benefit for people living in Western Sydney and the north-west and south-west growth centres.

However, not all reaction to the news has been positive with critics claiming that the initiative will result in even more pressure on Sydney Basin’s capacity by taking away already diminishing agricultural resources.

‘Feeding Sydney’ was the topic of talks at the recent one-day interactive conference, held at the Hawkesbury campus of the University of Western Sydney (UWS).

Held at the University of Western Sydney, the conference attracted attendees from a wide range of academic and industry backgrounds.

Talks at the conference focused on the issues and challenges facing major population hubs around the world at a time when available agricultural land and water supplies are declining and there is increasing pressure regarding sustainability of farming systems.

A mix of academic and industry professionals also explored possible alternative food supply options together with issues of food security.

Professor Phillip O’Neill (L), Director of UWS Urban Research Centre spoke at the conference as did Dr Gavin Ramsay from UWS Hawkesbury Foundation.

Speakers at the conference included National Water Commissioner Chris Davis (centre) advisor to Federal Minister for Climate Change, Penny Wong.

Professor Bill Bellotti, Vincent Fairfax Chair in Sustainable Agriculture and Rural Development UWS spoke at the conference, agreeing with Professor O’Neill that, based on food alone, it might be reasonable to conclude that agriculture in the Sydney Basin is insignificant.

Speakers included Professor Bill Bellotti, Vincent Fairfax Chair in Sustainable Agriculture and Rural Development UWS; Chris Davis, Commissioner of the National Water Commission; Professor Phillip O’Neill , Director Urban Research Centre UWS; Tristan Harris, G.M. Buying and Marketing, Harris Farm Markets; Mark Kable, Agricultural Director, Harvest Moon, Tasmania’s fresh vegetable specialists; John Webster, National Chief Executive, Foodbank Australia; and Dr Gavin Ramsay, Associate Head, School of Natural Sciences and Senior Lecturer in Rural Systems and Development UWS.

A grower’s and supplier’s panel discussion also provided a real world insight into the issues associated with the supply side of the equation.

Food security
Food security is determined by the food supply in a community, and whether people have adequate resources and skills to acquire and use (access) that food (NSW Health, 2003).

In the first plenary at the conference, Dr Gavin Ramsay gave a sobering overview of a possible future global scenario in his paper – Feeding the world: Pipe Dream or Possibility?

“The head of the international Monetary Fund (IMF) has warned that if food prices remain high, there will be war and other dire consequence for people in many developing countries,” Dr Ramsay said.

He added that the problem could also create trade imbalances that would impact major advanced economies, so it is not only a humanitarian question.

“The issue of food security is growing. China is eyeing overseas land in a push to secure more growing areas for food. Chinese companies will be encouraged to buy farmland abroad, particularly in Africa and South America to help guarantee food security, under a plan being considered by Beijing,” Dr Ramsay said.

“Saudi Arabia is doing a similar thing. According to information from Pakistan Ministry of Agriculture, currently Saudi Arabia is in talks with Pakistan to lease an area of farmland nearly twice the size of Hong Kong in a bid to ensure food security.”

Dr Ramsay also pointed out that Gulf Arab states are heavily reliant on food imports and, spurred on by a spike in prices of basic commodities, have raced to buy farmland in developing nations to guarantee supplies.

In his paper at the conference – Feeding Sydney: A Secure Future for Food? – Professor Bill Bellotti also talked of the “unprecedented uncertainty and complexity surrounding our agrifood systems.”

“The future challenge will be to produce more food from a shrinking resource base with less GHG emissions. But can we do it?” he asked.

“Food security is becoming a huge issue across the globe, including here in Australia. A recent study revealed that 22% of households in disadvantaged localities in Sydney experienced times when they ran out of food and the money to purchase more. Also according to figures from Foodbank Australia, a million children don’t get enough to eat so this is an alarming food security issue right here,” Professor Bellotti said.

Dr Ramsay explored the question of why food is such “a big deal”.

“The world’s population is growing, people are eating more food and often more expensive food (especially animal products). More expensive food uses more resources to produce,” he said.

“We also have to look at the nature of food. More than nutrition, it’s also about vitality and health. It’s also an incredibly important element in social activity. Then of course, it’s also very important for social status, for example, dining in an expensive restaurant shows others you can afford to.

“Also another important element is equity. In western society we eat differently from other parts of the world. We eat, for example, much more processed food and have much more resources available to us than in other parts of the world, particularly in Third World Countries so we’re talking about equity here,” he said.

Dr Ramsay cited several influencing factors responsible for the current world food crisis.

“Firstly, the climate seems to be changing. We are also running out of oil and are turning to biofuel production, effectively turning food producing land into land for houses,” he said.

“We are also destroying agricultural land due to inappropriate practices and we are running short of fresh water.”

In his paper Dr Ramsay also outlined the controlling factors behind the current international food system.

“Features of the system are that it is controlled by both public and private interests and a limited number of companies. It is controlled by the wealthy and is very production focused,” he said.

“Most of world’s population growth is occurring in urban areas of poor countries. These people are very food insecure – they can’t grow their own food. On top of this we are seeing huge changes in the patterns of food consumption, with a massive increase in the consumption of meat.”

Poor get poorer
“Many poorer countries are moving to become net importers of food not exporters. The number of food emergencies is also increasing from 14% to 27% in 2008. Resultant effects of these factors are that the poor and the vulnerable are hit even harder. In the areas I’ve worked in South Africa over 60% of the head of households were girls age 12. Most of this is due to the effects of HIV,” Dr Ramsay said.

“By 2050 there will be 9 billion people on the planet. What then are the implications for feeding tomorrow’s populations?

“All countries cannot be net importers of food. In fact, there are more countries than ever changing from being net exporters to net importers of food, therefore there will be an uneven distribution of food. Some will have too much, some too little.

“Those with too little will generally live in countries with poor governance and this has political ramifications as hungry, dissatisfied people are more vulnerable to political pressures and this will lead to a series of civil disturbances etc,” he said.

“If we cannot distribute food according to our needs now, will we be able to in 2050?

“In terms of food security, rich people (countries) who control resources (and manage them appropriately) are more likely to be food secure – but it is not guaranteed if they need to import food. However, poor people (especially the urban poor), will simply have no food security,” he said.

In his closing remarks, Dr Ramsay addressed his opening question of whether or not we can feed the world.

“It’s a possibility but it’s very much in the pipedream category,” he concluded.

Sydney’s food value chain
According to recent statistics, Sydney will grow from 4.2 million to 5.3 million people by 2030. These extra 1.1 million people will require 640,000 new dwellings with 160,000 of these to be built in the new north-west and south-west growth centres. Outside the growth centres another 60,000 dwellings will be constructed on greenfields lands. Then there is land needed for employment, which involves another 7,500 hectares.

In short, urban growth in Sydney has a large footprint.

“Beyond 2031 we know Sydney will continue to grow. Another million people by 2050 will mean a city in excess of 6 million people, which is large by developed world standards. And there may well be more after that. But these uncertain numbers are pretty much irrelevant,” said Professor Phillip O’Neill who presented his talk – Sydney’s food value chain: A discussion paper – to the Hawkesbury Foundation Conference.

Head of the Urban Research Centre (URC) at UWS, Professor O’Neill said the purpose of his paper at the conference was to “explore what we know about Sydney’s food value chain”.

“While some implications are drawn, its main purpose is to provide a knowledge base for further discussion and analysis,” he said.

“What we know is that Sydney’s food supply system and the basin’s agricultural lands are currently in crisis. The problem is that we know little detail about the crisis, its dimensions, its stakeholders, its impacts and its consequences. What we do know, however, is that there is alarming inattention by governments to the issue, let alone there being policies in the public domain for us to engage with.”

Professor O’Neill said that the task had been hampered by a marked lack of available data on the subject.

“We know little about Sydney’s food supply system. The Urban Research Centre has systematically tried to assemble the story of the task of feeding 4.2 million Sydneysiders. But it has proved difficult,” he said.

“The pertinent question for us to ask today is why was this task left to a group like ours to undertake without funding for labour or data? This neglect by government of basic information gathering is inexcusable.”

According to Professor O’Neill, in 2006, there were just 6,300 agricultural jobs in the Sydney Basin.

“They are located where you would expect, on Sydney’s NW and SW plains and along the orchard and poultry districts of the Central Coast,” he said. “The NSW Department of Agriculture estimates there are about 1,000 vegetable farms left in the basin. The ABS estimates these produce 43% of NSW vegetable production (by value). Poultry producers are also significant, contributing 42% of NSW poultry meat output and 48% of its eggs. Mushroom growers are responsible for close to 100% of NSW fungi supplies.

“But that’s about it. In total, Sydney’s agricultural output is just 8.5% of the value of our state’s total agricultural output, and under 2% of the nation’s total. In other words, aside from selected higher value fresh vegetables, and poultry and mushrooms, the Sydney Basin’s contribution to Sydney’s food needs is as meagre as it could be before you would describe it as insignificant,” he said.

“When the growth centres and other greenfields lands are transferred to urban uses, the NSW Department of Agriculture surveys show that 52% of the basin’s remaining vegetable farms will be eliminated. When this happens, then the basin’s agricultural significance – at least in its present format – will be lost forever, after just 221 years of white man’s custodianship.”

During his talk – Feeding Sydney: A Secure Future? – Professor Bill Bellotti gave an illustration of the farm gate value of agriculture in the Sydney Basin.

“As we can see the farm gate value of agriculture is around $1m with poultry, vegetables and cut flowers accounting for the top production values in the area,” he said.

“Sydney imports more than 85% of its vegetable requirements,” Professor Bellotti said. “And only 3-5 % of our average food energy consumption is produced in the Sydney Basin.”

Professor Bellotti agreed with Professor O’Neill that, based on food alone, it might be reasonable to conclude that agriculture in the Sydney Basin is insignificant.

“However, this does not account for environmental, aesthetic, recreational, and educational values, which are important.

“When community development benefits are valued, a different answer emerges,” he said.

“In terms of irrigation in the Sydney Basin (around 8000 hectares plus) there are competing claims on land and water where farmers are shifting to non-food options, which are more profitable and carry less risk,” Professor Bellotti said.

Freshwater consumption in NSW 2004-05

“Water for irrigation is already scarce, and will become scarcer in the future. So the question is should we prioritise allocation of land and water resources to food?”

In his paper – Feeding Sydney: the Water Question, Commissioner of the National Water Commission, Chris Davies, told the conference that it’s probably going to get drier, and water for irrigation is going to be hotly contested.

He made several recommendations as to the best future management of Sydney’s water resources.

“In the case of irrigation for agriculture in and around Sydney, river and dam allocations will be resolved through WSPs,” he said.

“Recycled water has to be used close to its source, nutrients should be left in water, where possible and urine separation is worth looking at.

“Small-scale irrigated agriculture is possible where sewer mining is permitted from decentralised schemes. Also opportunistically, rainwater or stormwater can be collected,” he said.

Despite the challenges for agriculture in the Sydney Basin, in food and beverage manufacturing, Professor O’Neill said that the food value chain is looking very healthy.

“Here we find over 30,000 jobs, 4000 in beverages (juices, soft drinks and beer mostly) and 25,600 in food manufacturing,” he said.

Food retail
Turning to the food retail sector, Professor O’Neill gave an overview of the major factors at play.

“There are 57,000 food retail workers in Sydney. Retailing jobs follow the population, especially the suburbanised population, especially in the suburbanised malls in and among the suburbanised population, like at Castle Hill, Warringah, Miranda and Penrith. But everywhere else too,” he said.

“Four sub-sectors account for 93.000 jobs, exactly one half of all Sydney’s food jobs: growing food, manufacturing food and drink, and retailing. Remember, just 6,300 of these jobs are in agriculture, producing less than 3% of the value added along Sydney’s food chain.”

Household consumption
“The concentration of employment in food services is reflected in what Sydney households spend their food money on. The standout spending category for Sydney households is meals eaten out and take away food. The next largest spending category is alcoholic beverages. Together these two categories constitute 38% of total household food and beverage consumption, or about 36 times what Sydney spends on its own fresh vegetable output,” Professor O’Neill said.

One implication of our spending so heavily on the higher value added food products and services – that is, where the actual food content makes us an increasingly small portion of what you buy – is that for the overwhelming majority of Sydney households, consuming fresh vegetables grown in Sydney is not an affordability issue. Rather, we choose, or are led, to buy food in other forms.

Professor O’Neill summed up his presentation, emphasising some major points:

“Clearly, Sydney-sourced fresh food attracts a meagre share of value flows in Sydney’s food economy. Sydney’s fresh food agriculture is threatened not only from diminished access to land and water resources, but also from its poor leverage over food industry value creation and distribution and poor leverage over Sydney households’ food spending patterns,” he said.

“Secondly, in the food market, agriculture has little market power and little capacity for competitive returns. But in the residential land market the food agriculturalist has significant market power and enormous capacity for high returns. Locked out of the food value chain, land-owning farmers instead choose, or are led, to the extraordinary gains available from selling rural lands to those who convert them to urban use.

“Much can be gained in understanding by analysing the food chain in terms of it being a competition between powerful players for the substantial consumer dollars on offer”, he said.

“That said, there is also much to be gained in understanding the food chain by analysing household consumption expenditure and householder food consumption habits. Sydney households in general are not poor. Their potential market power is enormous.”

Future scenarios
Professor Bellotti outlined three strategies for meeting future demands of population growth on Sydney’s food supply.

“The first scenario is the “Passive: Go with the Metro Strategy”. Following this strategy would lead to a further concentration of our food supply chains into a few major corporates and a loss of connection between food consumers and food producers,” he explained.

“Producers would also be forced into a global or national market, receiving low profit margins.

“The second is what I term the “Activist” strategy, which covers many different grassroots community movements,” he said.

“Basically, an activist rejects conventional agriculture, often striving for a high degree of food self-sufficiency.”

A third future scenario is the “Deliberate” strategy.

“This is where food security is taken seriously,” Professor Bellotti said. “It would involve a nationwide coordinated response to the challenge of food security.

“This strategy requires actions at all levels of society from national, state, local government levels to corporate Australia, communities and individuals,” he said.

Of the three strategies outlined, this one provides the best solutions to creating a healthy environment, farms, food and people and is underpinned by an integrated policy, science and practice.

“Food is the great integrator – healthy ecosystems are linked with healthy farms, healthy food and healthy people,” Professor Bellotti said.

“Government at all levels will focus on future food security (supply, access, affordability) while food consumers will be a driving force for change.

“We need to shift from being passive to becoming active food citizens – a citizen who not only has a voice in how their food is produced, but who also may be active in producing, purchasing and preparing their food,” he said.

“Part of this shift would see a strengthening of the relationship between food consumers and food producers, more direct food supply chains and a greater recognition by urban populations of their dependence on rural communities to supply their food needs.”

Issue 108: Intelligent Farm Management – Ghost Gully Produce

September/October 2009
By Steven Carruthers

Water restrictions and farm management issues have driven many growers to water-saving technology to ensure their operations are resource and cost effective. Ghost Gully Produce is an example of this technology playing a key role in intelligent farm management.

Seedlings are grown by the grower’s mother-in-law.

Ghost Gully grow seven lettuce varieties – red and green corals, oaks, minuettes and baby cos.

Farm infrastructure includes sand filters and a mist cooling system.

Gary and Kym Samuelsen.

Located in Gatton, Ghost Gully Produce is one of a handful of small family-owned hydroponic farms in the Lockyer Valley, in South East Queensland. Gary Samuelsen, a former dairy farmer, turned to hydroponic lettuce and herb production not long after the dairy industry deregulated. Seven years ago the family purchased a run-down 18 ha nursery, mostly scrub, with four small greenhouse structures (20m wide x 75m long). Gary replaced the plastic roofing with hail net and adapted the existing benching infrastructure to an NFT growing system using half-round stormwater pipes with soft plastic covers and slits to accommodate seedling plugs.

New infrastructure includes five growing systems under hail net.

The retrofit greenhouse structures have open-sides and hail net roofing.

“That got us started,” said Gary, “and then we met Joe who formulated our nutrient and introduced us to proper channel with clip-on lids.”

Joe Crane is a specialist consultant in the region with over a decade of experience in nutrient formulation, hydroponic system analyses and design, and farm automation, including cold room temperature logging. The collaboration has resulted in new farm infrastructure, including washing, packing and cooling sheds, five new NFT growing systems under 1 ha of hail net, Black Max ozone water disinfection equipment, and a WiSA water management system.

Water Management System
The Australian-developed WiSA system was primarily designed as an irrigation system for field farming to enable precise control of water and nutrient applications. The system is connected to a dedicated PC 24/7 to get the optimum data and utilisation of equipment. Following a number of below average rainfall years and severe water restrictions in South East Queensland, Joe took it upon himself to redesign the system for hydroponics. WiSA was so impressed the Victorian-based company appointed Joe its Queensland distributor, and Ghost Gully Produce became the first hydroponic farm to adopt WiSA water-saving technology.

“Stage 4 water restrictions meant we had to reduce water usage by 25%,” explained Joe. “The WiSA system allowed us to attain 33.3% water saving,” he added.

When Gary first started the business he used town water but was beset with problems including Pythium and occasionally over-chlorination. Today, he uses a combination of town and dam water and ozone disinfection.

The farm operates six large storage tanks, each holding 95,000 litres.

Aquatic weeds minimise water evaporation.

From the dam, the catchment water is pumped into three large storage tanks (95,000L each) where it is treated with Sporekill to reduce the pathogen load. When required, the water is transferred to duplicate upper level storage tanks with in-line ozone (O3) injection to ensure the water is free of pathogens. The upper storage tanks supply clean water pumped to eight growing systems on the property.

Dam water is first treated with Sporekill to reduce the pathogen load.

Each growing system has its own dedicated reservoir tank (10,000L), dosing equipment and ozone generator. In total, the farm operates 14 Black Max ozone generators at strategic points throughout the water system to prevent water-borne diseases.

The WiSA system works in real-time, that is, what is happening now, not last week. Variable factors such as water usage, farm tank levels, system pressures, nutrient conductivity, pH, temperature (air and water), humidity, rainfall, nutrient dosing times and valve timing are monitored and logged by the WiSA system.

Joe Crane explains the WiSA system with automatic nutrient dosing.

Sensors monitor air temperature and humidity.

“These variables are the basis for automated decision-making on the farm, and can be graphed and recalled individually and comparatively over time periods for farm management decisions,” explains Joe.

The WiSA system manages variables in real time.

The level of monitoring also extends to the washing shed and cold-room where sensors record temperature in 30-second increments.

“In the event of a dispute over cold-chain management, we’ve got the records,” said Joe.

An interesting aspect of the WiSA management system is nutrient management. By analysing the conductivity factor and water temperature of the nutrient reservoir, the conductivity can be adjusted according to water temperature on a floating scale. Nutrient is added to increase CF via automated dosing pumps, and CF is decreased through plant usage.

“The computer scales the nutrient formulation for us,” explains Joe. “Most of the time we run so long that we only dump when it rains,” he added.

The farm’s nutrient formulation process is proprietary to Joe’s consultancy business, Cyber-Hydroponics, with nutrient formulations uniquely tailored to suit water supply, individual crops, and to account for seasonal variations in temperature. Farm formulations are prepared by the farmer, offering a cost saving over conventional nutrients.

At first, the use of multiple Black Max ozone generators (BM2s) at different points in the water system seems excessive.

Gary Davies from Black Max explains the ozone injection system.

“The farm is spread over a large area and it was more practical to use multiple units,” explains Gary Davies, principal of Adelaide-based Black Max Ozone Generators. “A smaller, centralised farm would not require as many units” he said.

The Australian-made Black Max ozone generator was first introduced to the hydroponics industry in the late 1990s, at a time when many growers were unaware of the benefits of using ozone, or O3, to disinfect water. It is one of the most effective bactericides known to science. On the oxidation chart it is listed above chlorine, iodine and bromine, but unlike these chemical options for disinfection, ozone dissolved in water breaks down to oxygen in 15-20 minutes, leaving no chemical residues.

Ozone generators are linked to disinfect dam water.

System reservoirs are coated with insulation to keep temperatures warmer during winter and cooler in summer.

Ghost Gully uses the BM2 unit, which produces 2.6mg of ozone/litre of air for treatment of reservoirs up to 10,000 litres. Black Max also makes the smaller BM1 that produces 0.6mg of ozone/litre of air, for treatment of any size reservoirs up to 2,000 litres. Housed in marine grade aluminium casings, the BM1 and BM2 use a high quality ozone-producing UV lamp operating at a precise wavelength. The units have a small see-through window to easily and quickly check lamp operation. Ozone is introduced in-line using the ‘venturi’ principle, a vacuum effect caused by a reduction in fluid pressure that results when a fluid flows through a constricted section of pipe.

Both the grower and Joe are convinced about the effectiveness of ozone. Joe recalls an incident when an ozone lamp failed and a pathogen problem became evident in one section of the farm.

“Gary called me the next day about a problem on the farm, something we hadn’t seen for a long time,” recounts Joe. “We quickly worked out that an ozone lamp had failed after several years’ use. We put a spare unit onto the system and the problem quickly disappeared.

“There is no doubt in our minds about the effectiveness of the ozone system in pathogen control.”

Ozone is also used in the washing water to remove bacteria, fungi and moulds, and is said to extend the shelf-life of produce. Trials at Ghost Gully Produce point to a 3-week shelf life once lettuce leaves the cold-room.

Harvesting is made easier using a re-engineered ground lettuce harvester.

Ozone bubbles through the washing water.

Higher yields, quality and longer shelf-life are attributed to ozone treatment.

“They just last longer,” said Gary Samuelsen.

The longer shelf-life could also be partly attributed to a twice-weekly foliar spray of SilikaMajic, a potassium silicate-based product from Flairform (

“It’s got to be a good thing,” said the grower. “It promotes cell growth and slows down transpiration. In summer, lettuce stay good for an extra 2 days, longer than normal without it,” he added.

According to Joe, ozone is extremely effective at controlling water borne diseases such as Pythium.

“Pathogens are always there,” he explains, “but ozone keeps them under control.”

He added that pathogens are hardy and likely to harbour in irrigation lines.

“Most are eliminated when the return water reaches the system reservoir, which is ozonated 24/7,” he said.

“I recommend that all my consulting farms use the ozone sterilisation method. As well as being effective, the Black Max units are robust and have an excellent life.”

At under $1,000, the Black Max ozone generators are supplied with a fully assembled installation kit consisting of 3 metres of ozone hose, non-return valve and ozone jet (venturi). Accessories include a ‘maxizone’ injector that requires a minimum flow rate of 1,800 litres/hr and a ‘megazone’ injector manifold requiring a minimum flow rate of 9,000 litres/hr, to suit 1-2 hp pumps.

Final remarks
With an annual production capacity of over a million plants and plenty of room to expand, Ghost Gully continues to be a work in progress.

Water-saving practices start at the dam, which has been allowed to grow over with weed to minimise evaporation. It also eliminated the large duck population that once frequented the dam.

“If ducks can’t see the water, they won’t land,” quips the grower.

On-farm water-saving practices also include capturing overflow rainwater, referred to by the grower as “God’s nectar”, from the building structures and growing systems. All the system tanks have overflows that route excess water to a lower catchment tank (38,000L). When the water reaches a certain level it is pumped to the upper storage tanks.

But the heart of the operation is the WiSA water management system that allows produce to be turned over from seedling to market in a way that’s both resource and cost-effective. Recording variables such as water usage and storage and processing temperatures assists with the farm’s water efficiency program and Quality Assurance compliance.

Ghost Gully has shown that ozone disinfection is simple and efficient, with benefits including higher yields and quality and longer shelf-life, and no chemical residues. Where ozone disinfection was once cost-prohibitive for many small and larger growers alike, the Black Max ozone systems are affordable.

Ghost Gully Produce is a highly successful operation and a prime example of automation playing a key role in intelligent farm management.

For further information contact:
Gary Samuelsen
Ghost Gully Produce,
2 Rangeview Drive, Gatton Old 4343
Ph: 07 5462-5502
Fax: 07 5462-5504

Joe Crane
PO Box 3918, Burleigh Town, Qld 4220
Mob:0416 232 030
Fax: 07 3319-0926

Gary Davies
Black Max Ozone Systems,
PO Box 429, Noarlunga Centre, SA 5168
Ph: 08 8327-3150
Mob: 0408 825 511
Fax: 08 8327-3144

Graeme Wright
WiSA Irrigation Solutions,
PO Box 592, Echuca, Vic 3564
Ph: 03 5480-7713
Fax: 03 5482-3736

Issue 90: Preliminary observations on simplified NFT

September/October – 2006
Author: Dr Allen Cooper

Growth of the spring cabbage plants was vigorous and very healthy.

Dr ALLEN COOPER demonstrates that water taken up by plant roots is not lost solely from the leaves, but that a large amount is lost from the roots themselves. In this article, the father of NFT documents four scientific firsts, including correlations between day-length and nutrient uptake, between nutrient uptake and the direction of change in day-length, and the photoperiodic relationship with the interaction of day-length and the direction of change in day-length.

At the age of 83 I do not have many years left in which to complete the development of a cheap, simple form of NFT. I am therefore publishing, while there is still time, the information that I obtain as soon as I obtain it in the hope that if I do not have the time left to complete the work, someone may have become sufficiently interested to finish the job. It may be an imprudent course of action but I know that I shall not live to regret it.

It is well established that plants do not grow sufficiently well in a static nutrient solution to produce a crop. Even bubbling oxygen into static nutrient solution is not sufficient to ensure the long-term maintenance of plants or good growth. A minimal requirement in water culture is the re-circulation of a sufficiently large total volume of nutrient solution. The simple form of NFT that I am trying to develop requires no electricity to achieve the circulation. The plants themselves provide the motive power.

There is much about the functioning of plants that has never been questioned. There are widely held beliefs that are accepted as being true without ever having been tested. These believed “truths” are sometimes not explicitly stated but are tacitly implied. The very general subject of plant metabolism provides an example. A visit to a cowshed shows that animal metabolism is imperfect. The organs of the cows for excreting the waste products of their metabolism are clearly apparent and the products of excretion are even more apparent. However, it is tacitly implied that plant metabolism is perfect, presumably because the organs of excretion are not apparent and the products of excretion are even less apparent. Another example of the mythology in plant physiology is the belief that roots absorb water and leaves lose it. Like many beliefs with conviction there is an element of truth in this belief but it is not the whole truth.

A critical examination of the spatial growth pattern of Helianthus annulus throws some light on both of the above beliefs. H. annulus is a perennial plant that, as its name implies, grows with the passing of the years in the form of a ring. If a young plant of H. annulus is placed in the bare soil in the centre of the ring it will die. However, if the soil is removed from the centre of the ring and all root material is carefully sieved out of the soil and the soil is thoroughly washed before being replaced in the centre of the ring, then a young plant will grow well in the centre of the ring. A large scale version of this “poisoning” of the soil is provided by the peach tree replant problem in California where it is well known that young peach trees have been grubbed.

Fundamentally, plants are not very different from animals. In the nineteenth century in London when the products of human excretion were separated from one of the main products for ingestion, namely the water supply, mortality decreased dramatically and population growth escalated. This analogy suggests the untested possibility that in both H. annulus and in peach trees the organs of ingestion and the main organs of excretion are the same organs, namely roots.

It is obviously impossible for the volume of soil in which a plant is growing not to have moisture gradients within the volume of the soil. It is reasonable to make the untested suggestion that the roots at the wet end of a moisture gradient absorbs water that contains nutrient while the roots at the dry end of the gradient excrete liquid containing the waste products of metabolism, in other words plant urine. There is no need for an anus because, unlike animals, plants do not ingest solid food. The leaves are ideally situated to handle gaseous ingestion and the excretion of gaseous waste products of metabolism. Thus, in both leaves and roots the same organ may be capable of both ingestion and excretion. The closest analogy in animals is the mouth that is capable of both swallowing and vomiting.

The above suggestions rest on the ability of “wet” roots to absorb liquid and the ability of “dry” roots to exude liquid. To test this hypothesis I set up a horizontal length of roofing gutter closed at both ends, and beside it and touching it a very slightly sloping adjacent gutter open at one end. The open end was sited above a bucket. Spring cabbage plants were propagated in pots filled with soil until there was sufficient root growth to enable the mass of roots and soil to be slit vertically with a knife from the base upwards to provide a plant with a root system divided into two parts. The plants were placed astride the touching gutters so that one half of the root system was in the horizontal supply gutter that was filled with nutrient solution and the other half was in dry drainage gutter.

The spring cabbage plants were grown outdoors in the simple equipment from September to April inclusive. The volume of nutrient solution in the supply gutter decreased progressively until it was replenished, and a considerable volume of liquid was collected daily in the bucket under the open end of the drainage gutter. There was no doubt that the “wet” roots were absorbing liquid and the “dry” roots were exuding liquid. In this way the plants provided the motive power that achieved the circulation of the nutrient solution without a need for electrical power. Re-circulation could have been achieved by manually emptying the contents of the bucket into the supply gutter. Millennia ago the Egyptians perfected a simple technique for lifting irrigation water that is still in use.

The photograph (please ignore the stone trough; it was too heavy for me to move) shows that the growth of the spring cabbage plants was vigorous and very healthy, suggesting that the plants had benefited from being provided with a dining room separated from their lavatory. Like the Victorian Londoners and H. annulus, they seemed to thrive when not forced to ingest waste products of metabolism. However, this is an untested concept of plant mythology that was fashionable only until the nineteenth century when the work of the German chemists led to the founding of the artificial fertilizer industry and created the resulting increases in crop yields. It is a concept that has remained unfashionable ever since and has been little examined.

Correlation between day-length and nutrient uptake
Another item of plant mythology is the belief that some aspects of plant growth and development are controlled by day-length per se. An enormous amount of work has been done on the influence of day-length on flowering despite the fact that flowering provides a very limited assessment of the influence of day-length on the physiology of plant growth and development because flowering is a fairly discrete response and its progress is difficult to follow without destructive sampling. What is required for study is, firstly, a response to day-length that is continuous and, secondly, a non-destructive method of measuring the response continuously or, at least, daily.

The work that has been done on the response of flowering to day-length has been done in constant day-lengths. In most of the world constant day-lengths do not occur but, despite this the myth has arisen that the same response to day-length obtained in constant day-lengths will apply in day-lengths that are increasing or decreasing. In other words, the response to day-length will be the same in an increasing day-length as in a decreasing day-length. The validity of the assumption has never been tested. The mythology would be in trouble if it were found that plants do not respond to day-length per se but to the interaction between day-length and the direction of change in day-length.

In order to ensure good plant growth I concerned myself with changes in the concentration of the nutrient solution and the maintaining of concentrations that were favourable to plant growth. Consequently, detailed data were obtained daily on the changes in concentration to decide whether to add water or nutrient solution to the supply gutter. The electrical conductivity of the liquid in the supply channel and of the liquid draining from the drainage channel was measured daily. These data are shown in Diagram 1 as the reduction in the cF of the liquid in the drainage channel relative to that of the liquid in the supply channel. Although the electrical conductivity of the liquid in the drainage channel would be increased by the excretion of any waste products of metabolism, and reduction in the cF of the liquid in the drainage channel relative to the cF of the liquid in the supply channel would provide a measure of nutrient uptake.

To eliminate any short-term fluctuations so that the long-term trend could be seen clearly, the data in Diagram 1 are for 10-day means plotted against the time of year. There was no significance in using 10-day means; it merely made the arithmetic easier. The data show that from late September to early November (i.e. from A to B) nutrient uptake decreased, whereas from early November to mid-December (i.e. from B to C) it increased. In mid-December a pronounced discontinuity occurred (i.e. between C and D) when the highest recorded uptake was followed by a very low value. From late December to mid-February (i.e. from D to E) nutrient uptake increased. The subsequent pattern of nutrient uptake (i.e. from E to F) was not well defined.

In looking for an explanation of this seasonal pattern of nutrient uptake, the discontinuity in mid-December is a good starting point. The greatest nutrient uptake occurred on the 8th of December, and the subsequent very low value occurred on the 18th of December. Therefore, an approximate estimate of the date of occurrence of the discontinuity is the 13th of December. What happened about this date?

The data in Diagram 2 suggests a possible answer to the question. In this diagram the day-length experienced by the plants in minutes from sunrise to sunset at the latitude of 50O 45′ N (the location of the experiment) has been plotted from early December to early January. Throughout early December the day-length progressively and regularly decreased, but on the 15th of December the regular daily decline in day-length ceased. The close correspondence between this date and the date of the discontinuity in nutrient uptake suggests the following hypothesis for disproof.

Correlation between nutrient uptake and the direction of change in day-length
There was a biochemical mechanism within plants that was detecting the direction of change in day-length. Immediately the decline in day-length ceased the relation between day-length and nutrient uptake changed. If this were correct then it would follow that plants were responding, not to day-length per se, but to the interaction between day-length and the direction of change in day-length. This possibility is shown in Diagram 3 where the reduction in the electrical conductivity of the liquid from the drainage channel relative to that of the supply channel is plotted against day-length in both decreasing day-lengths. The same lettering of A to F has been used as in Diagram 1. The data obtained in decreasing day-lengths are shown as open circles; the data obtained in increasing day-lengths are shown as solid circles.

It can be seen that in a declining day-length of not less than 564 minutes (the day-length of the 8th of November at the location of the experiment), nutrient uptake decreased as the day-length decreased (A to B). With further decrease in day-length, nutrient uptake increased as the day-length continued to decline (B to C).

In an increasing day-length, nutrient uptake increased (D to E) with increasing day-length until a day-length of 608 minutes was reached (the day-length of the 16th of February at the location). With further increase in day-length (E to F) the relation between nutrient uptake and day-length was not well defined.

It is of interest that the influence of day-length on nutrient uptake between E and F appeared to be less dominant than in other day-length conditions, presumably because other influences were capable of affecting the relationship when the day-length was greater than 608 minutes and was increasing.

Despite this variability of response there appeared to be an optimal day-length of 608 minutes for nutrient uptake by spring cabbage plants when the day length was increasing.

It would be interesting to see if the volume of water lost by the roots is also dependent on the interaction of day-length and the direction of change in day-length. If nutrient uptake is responding to such an interaction, it is reasonable to suggest that excretion would react correspondingly.

The correlation between nutrient uptake and day-length is obvious from the data. What is required is a controlled environment facility in which to determine whether the relation is casual. The use of a divided root system as described earlier would provide a simple, very sensitive method of exploring the responses of root physiology to the environment in a controlled environment research facility. It would provide both a response to day-length that was continuous and a non-destructive method of daily or even continuous sampling. Such an exploration would enable much of the potential of a simplified NFT system to be achieved. It might even make the difference between the long-term operational success and the failure of the simplified form of NFT by obtaining a greater understanding of the influence of the re-absorption of the waste products of metabolism on plant growth and development.

Preliminary indications are that re-absorption hastens the passage from root growth to shoot growth to leaf growth to fruit growth to death, and increases the amount of growth of each stage. The growth regulatory chemical involved might even be identified. The possible potential for the control of development of the part of the plant that is to be marketed is obvious. Applying artificial fertilizers merely increases the growth of the whole plant. Precise targeting would be a commercial advantage.

Surely there is a plant physiologist somewhere who is interested?

For further information contact:
Dr Allen Cooper,
23 Longlands,
Worthing BN14 9NW,
United Kingdom.

Issue 83: Aquaponics Simplified

July/August – 2005
Author: Wilson Lennard

WILSON LENNARD outlines his research to develop a successful recirculating aquaponic system to produce Murray Cod and lettuce, with significant savings in water use and zero environmental impacts.

I came to the world of aquaponics from the other side , that is, the aquaculture side. Freshwater aquaculture is moving into a new phase and a lot of people are now turning towards using large, environmentally controlled indoor recirculation systems to grow fish. These systems are a self-contained unit, usually located in an insulated shed. These are high intensity systems, with tons of fish being produced annually on very small land areas. The advantage of recirculating fish farming is that water is recycled through the system, and is therefore used to its full advantage.

The downfall of any aquaculture operation is that fish produce waste, and this waste needs to be disposed of in a way that won’t impact on the environment. Fish waste is nutrient rich and if it is disposed directly to the environment, it can have negative consequences. This is where aquaponics and I come into it.

I was looking for a way to filter the nutrient-rich fish waste out of aquaculture systems. Solid fish waste is constantly removed from these systems and is usually composted, so it is not much of a problem. It is the water-bound fish waste that is a problem.

Around 70% of fish waste is actually water-bound, arising from the gas exchange of ammonia-type waste that the fish excrete across their gills. It is this water-bound component that I was looking to treat. So, from my point of view, I was looking for a way to remove water-bound waste from our fish culturing systems. This is required because fish farmers at present change approximately 10% of their water every day, to counteract this build-up of waste. Ten percent may not sound like much, but in a system containing 100,000 litres of water (which is not a large system), that means removing 10,000L of water a day, finding a way to dispose of it, and replacing it with 10,000L of clean, fresh water. So, as I said, I was coming at the problem from a fish culturalist perspective.

The great thing about this water-bound fish waste is that it is mainly nitrates and phosphates. As all hydroponic plant growers know, these are some of the main nutrients used for hydroponic plant culture. So the question arose, can these fish wastes be used as plant nutrients? This is where I started after obtaining a PhD scholarship through the Rural Industry Research and Development Corporation (RIRDC).

I set about designing and building an aquaponic system to integrate fish culture with hydroponic plant culture. I had to design a very small-scale system, as I needed to be able to replicate my experimental situations for scientific purposes. So I eventually ended up with 12 aquaponic units that were identical to each other.

A unit consists of a 100L fish tank with an associated biofilter. The biofilter is very important to the fish’s health, as it converts harmful ammonia released by the fish into harmless nitrate. Above the fish tank is a shelf containing a hydroponic gravel bed. Water can be pumped from the fish tank, up to the hydroponic gravel bed, and then returns to the fish tank. That’s it. It’s pretty basic, but it really works.

The theory behind aquaponics is this:the fish live in a tank, eat fish food, and produce two types of waste; solid waste (fish poo) and water-bound waste. As I said earlier, solid waste is routinely removed and generally composted. The water-bound fish waste is actually the same nitrate and phosphate hydroponic farmers add to their systems using inorganic salts that they purchase.

What was fish waste, is now plant nutrient. The water from the fish tank is pumped to a hydroponic plant culturing component and the nitrate and phosphate from the fish is used to feed the plants. The water, now ‘cleaned’ of nutrients, is then returned to the fish tank and the whole cycle begins again.

If the amount of waste the fish produce can be balanced with the amount of nutrient the plants require, then we should have a system where we can perpetually grow fish and plants in the same water, with no water replacement required, other than that used to replace transpiration from the plants.

So I set about running a number of experiments to develop the idea within an Australian context. Some of the questions that arose were:

– does this aquaponics thing really work?
– can Australian fish species be used?
– what pumping rates are required?
– what hydroponic systems can be used (gravel bed, floating raft, NFT etc.)?
– are there any nutrient deficiencies in the plants?
– is the system productive in a commercial sense?

The question of does the aquaponic process actually work was answered with my first experiment. One kilogram of fish was placed in the tanks and 20 lettuce seedlings planted. The fish were fed, the system monitored and the fingers crossed. It is an amazing thing to inspect an aquaponic system daily and watch both the fish and plants grow and thrive. After three weeks in the aquaponic system, I had harvest size lettuce (around 120g, Green Oak fancy heads), fish that had grown, and water with 80% less nutrient in it than the fish-only controls.

This was definitely a good way to start for a PhD student -success! The fish were healthy and had grown at a rate the same as the industry standard, with no side effects. In fact, they actually seemed to like their new, cleaner environment. The lettuce plants were full of head and a beautiful, rich green, with no signs of nutrient deficiency.

At this point I was wondering, is there really three years of research in this? What followed was two and a half years of further experiments and trials to try and optimise the system for better plant growth and better nutrient stripping from the system.

Well, we now have a system that is fully optimised and is ready for commercial trials. Some of the variables that you may be interested in include:gravel beds work better on a constant flow water delivery regime.

Past hydroponic research has suggested that a ‘reciprocal flow’ (water is pumped to the gravel bed now and then, instead of a constant flow) was better as it aided water oxygen levels and distributed nutrient to plants better. This may be true in standard hydroponics, but we always require oxygen above 5mg/L for our fish, so oxygen is always above what the plant roots require (around 2mg/L for lettuce).

Our constant flow gravel bed system grows lettuce about 20% better than a reciprocal flow. Gravel beds and floating rafts are about 15-20% more efficient than NFT. My experiments have proven, within an aquaponic context, that NFT is less efficient at plant growth and nutrient stripping.

The last key finding is that we need to use a potassium and calcium-based buffer system. Fish farmers use sodium bicarbonate and similar basic salts to make sure the pH doesn’t drop. Fish systems are the opposite to hydroponic systems – as fish eat and metabolise feed, the water pH drops.

To counteract this pH drop, we use buffers to keep the pH up around 7. If we use potassium and calcium-based buffers, we can add the potassium and calcium to the system that the plants require for good growth.

So I had better tell you of the key findings. Fish (we used Murray Cod) and plants (we used lettuce) can be grown in an integrated aquaponic system. If the correct balance is met between plants and fish, no nutrient build-up occurs in the system, and the plants get all the nutrients they need.

We don’t get conductivity build-up or drop-off;it stays constantly at about 500mS/cm. This is because the fish renew the nutrients every time they are fed, which can be as high as 3-4 times per day, and the plants constantly use those nutrients.

A combination of potassium and calcium is used to buffer pH and provide the other essential plant nutrients. We also add a little chelated iron, as fish food is lacking in iron and the plants require it to produce chlorophyll. That is all we add to the system – fish food, a little buffer each day, and a little iron once a week. All the micronutrients required for the plants are in the fish food, so we don’t need to add any of these.

There are several advantages; some relate to the fish and some the plants. Because we can balance the nutrient output of the fish with the nutrient uptake of the plants, we never need to exchange water. We do need to replace any water lost through plant transpiration, but this is a small amount. We are now saving above 90% of the water a normal recirculating fish farm would use. So, the system is very water friendly. We have no nutrient-rich waste output, we use our nutrients to feed the plants, and we have zero environmental impact.

Our fish grow just as well as they do in any other fish system. The best outcome is that we grow healthy, strong plants that yield at the same rate as they would in standard hydroponics. That’s right, our lettuce grew just as well in our aquaponic system as they did in our hydroponic controls. So, the advantages are:

– excellent fish and plant growth
– zero environmental impact
– efficient water use
– yields as good as the prospective stand-alone industries, and
– the ability to grow two cash crops (fish and plants) off the one food source.

I am now building a commercial-scale aquaponic system. We will have the ability to grow around 500kg of fish a year and harvest 3,000 lettuce per week. We will have no environmental impact and will use less than 10% of the water a normal recirculating fish farm would use. The only other question is whether we can obtain ‘Organic’ certification? If we can achieve this, we believe we are on a definite winner. But more about that in a coming issue.

About the Author
Wilson Lennard is in the final stages of his research into aquaponics at RMIT University, Melbourne, Australia. He believes aquaponics is a new and emerging industry that will fill a defined niche in the aquaculture/hydroponics market.