Category Archives: Plants Food Animals

Growing things

Aquaponic System Maintenance

Our system has been running for a few months now, and I thought I’d share my maintenance schedule.

Daily

  • Feeding – feed fish morning and night. Feed yabbies every second day after removing any uneaten food pieces.
  • Check water temperature.
  • Check pumps and plumbing. To conserve power, I use a timer on the pump to operate it during daylight, and a timer on the aerators during the night. Check them.
  • Check that all siphons are operating correctly.
  • Pick vegetables as needed, while checking for bugs and disease.

Weekly

  • Test water for pH, ammonia, nitrites, nitrates and dissolved oxygen.
  • Check water level in sump tank and top up as required.
  • Plant out new plants after removing spent plants. Plant need seeds as required for planting out in 2-3 weeks time.
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Testing Water in Aquaponics

It is important to monitor ammonia, nitrites, nitrates, temperature and the pH level of the water, to ensure that they are in ‘range’. If not, you need to take corrective action otherwise fish and plants may die or succumb to disease.

Equipment

  1. Test kit. Most aquaponic gardeners use the Aquarium Pharmaceuticals Inc. API Freshwater Master Test Kit. This kit is inexpensive (about $AU47.00 at writing time) and is easy to use.
  2. Thermometer. Get a submersible one. Water temperature is important as it affects fish health and plant growth.
  3. Dissolved oxygen measurement. This can be done with a kit or a meter, and gives an indication of the aerobic activity in the system, which is important to the bacteria, the plants and the fish. The most accurate measure is obtained by using an electronic one, but remember that you get what you pay for.
  4. pH meter. Nice to have, as it speeds up the measurement of pH, which is very important.
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Locating Your System

Before starting to create your aquaponics system, you should give some thought as to where you are going to put it. In many cases, you may not have a choice of locations. If you do have a choice, it is important to consider that the chosen site will get 4-6 hours of sunlight on the grow beds and none at all on the fish tanks if possible.

Sun on the fish tanks helps algae to grow. Growing invasive plants on the top of the fish tank provides shade and shelter for the fish.

Some other factors to consider are:

Access to power. You need power to operate pumps and aerators, so they are best located near existing power sources. Running long extension leads is not the best because of voltage drops and the danger associated with them.

  • Access for planting, harvesting and maintenance. When the growbeds are full of plants, it can be very hard to reach over to the back of them to harvest or replant. Many plants will hang over the growbeds, so it is a good idea to leave at least 750mm between the growbeds. Access to all sides of the fish tanks is also very important, as fish can be hard to catch. We’ve planned our system to allow wheelchair access, as well as skidsteer access for adding more components as we expand the system.
  • Seasonal differences. There are large differences between the summer and winter sun tracks. Make sure your chosen site gets enough sun in winter.
  • Existing vegetation. Don’t place your system under deciduous trees or plants that have a heavy blossom drop. Some of these plants are poisonous to fish and even affect plant growth.
  • Children and pets (including chooks!). Make sure your system is child and pet friendly and safe. We’ve had issues with chooks eating all of our lettuce and salad greens – they weren’t happy with the leftovers!
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Water and Simple Living

The following us an updated version of an assignment submitted for my study in Writing the Zeitgeist at Curtin University.

Live simply so that others may simply live – Gandhi.

The other night, while watching the SBS program ’Go Back to Where You Came From’, I was struck by segment of the program about the woman in the Ethiopian UNHCR camp, who had to walk over one kilometre with containers to get her daily water supply. When she arrived at the water taps, with the film crew and show participants, there was no water. The camp had been in this location for over three years. In the background was a high, strong security fence, with rows of new four wheel drive vehicles and trucks for the UNHCR staff. Surely, after more than three years of existence, there would be a much better water supply, as well as better housing for the refugees.

This story segment which included all the tents, flapping in the desert wind, brought back to mind the quote from Gandhi. Where have we, as a species, gone wrong? Why do we have wars and conflicts? Is is just because of greed – of wanting more? By us wanting more, someone is going to have to miss out. Food supply experts have stated that there is enough food produced in the world to eliminate hunger, but that the problem is most of it is used for the production of livestock feed to produce meat.

One looming problem that mankind has to solve is the coming shortage of water. Peak oil is a problem already being widely discussed, but peak water is something that is being overlooked in many countries. It is estimated that by 2025, two out of three people will face water stress; that is, they will not have enough water for their daily need. An Australian example of this problem was experienced during the recent drought in the Murray-Darling Basin and the pressure on water supplies to Broken Hill, Adelaide and other towns in the basin. Water stress is also evident in places like Yemen, and in many other African countries. One of the problems with meat production is the amount of water that is required for each kilogram produced. With the growing world population, by 2050 experts have forecast that there will not be enough water to grow the animal feeds required .

So how much water do we consume each day, apart from what we drink from the tap? A 125ml glass of wine with dinner – 120l, a 250ml glass of orange juice – 170l, a hamburger – 2400l plus an egg which adds another 135l, the cotton t-shirt that I wore today – 4100l, and the shoes I’m wearing – 8000l, one sheet of the A4 paper that was used to print this essay – 10l, and between 16,000 to 100,000l per kilo of beef. Every country that exports food, is also exporting water .

I live a lifestyle that many people find hard to accept in the area where I have my home. I have no mains power, only solar with a backup diesel powered generator. All my water comes from either tanks collected from the buildings I built myself from local timber (well, I did buy new corrugated iron), or from run-off into a couple of dams. The dam water is used for toilet flushing and water the animals (chooks, dogs, macro-pods, and birds) orchard and plants around the house that provide nectar for the birds and insects, and something nice for us to look at, and a fire break of sorts. Our house is mostly constructed from mud bricks that we have made ourselves, with all the timber being cut by me from either the property or local native forests.

When we first moved here, we lived in a tent, and had to cart water. I can empathise with the refugees. It took a few years to get the shed built, the solar panels installed and tank attached because I was working full time. It was great to have 24×7 power again, as well as running hot and cold water. I put water into the house of my great aunt, who was born on January 1st 1900, in the late 1970’s. She had carried water into the house all of that time for washing clothes and dishes. She did have a flushing toilet and shower (hot water from a chip heater).

All of the doors, windows, shelving, kitchen cupboards and the like are recycled. I will admit to having a digital TV and a Blue-Ray player for entertainment. We did investigate installing a composting toilet, but after having used them in National Parks and roadside rest areas, decided that health and cleanliness was of greater importance. The water that does come out via a reed bed is used to water some trees and plants that provide shade and shelter, so I don’t consider the toilet to be a great water consumer.

I was raised in a family of six, with my paternal grandmother living with us as well. We had dams for the garden, but only a 15,000 gallon rainwater tank for the household and washing utensils in the dairy in a 25 inch rainfall area. As a result, the family was extremely careful in using the rainwater. We did run short on occasions. It still pains me to see taps dripping, water cisterns leaking, and lawns and gardens being irrigated. It also causes me angst to see farmers still using flood irrigation for low value crops and growing grass for cattle.

The future for the water in the Murray Darling Basin (MDB) is causing many problems for all people concerned: the people who live, and work there; politicians both federal and state; as well as those who depend on the water from it. The MDB is vitally important to the food production and export income of Australia, as it ’ generates 39% of … the agricultural income, 53% of Australia’s cereal production, 95% of the oranges, 54% of the apples, 28% of the cattle herd, 45% of the sheep herd, and 62% of pig herd’ . Only 4% of the rainfall in the basin is run-off for dams and rivers; the rest evaporates or drains into the ground. Over 35% of the runoff occurs from 12% of the basin area in catchments of the Murrumbidgee, Upper Murray, Goulburn, Broken and Lodden Rivers .

Professor Tim Lang introduced the concept of food miles in 1990, the aim of which was to ’highlight the hidden ecological, social and economic consequences of food production to consumers in a simple way, one which had objective reality but also connotations’. His article was important in raising awareness of the issues relating to where food is grown and the cost of transporting it to where it is consumed. A 2008 Choice report states that ’ a typical basket of groceries from the supermarket has “food miles” equivalent to two loops of the globe’ .

Another way, and it has been suggested a better way of analysing the true cost of food and our other requirements is via life-cycle analysis, which takes into account the inputs and outputs of energy involved in production, processing, packaging and transport of the food to the point of purchase, as well as air, water and waste pollution, and resource depletion.

We all need to be very conscious of our consumption patterns, choosing our foods very carefully. It’s very easy to buy the house labels at a low cost, when we all need to save money. Sometimes those foods are produced at a cost to the foreign countries farmers, who don’t have enough food or income for themselves, or they grow them in place of their own food for their own consumption. This is demonstrated by the clearing of Amazon rainforest to grow soy beans for export to Europe for cattle food and oil production, leaving the local people without food.

By growing our own foods as much as possible, even with a patio or balcony garden or small aquaponics system, and being aware of the water used to produce our foods, food miles and life cycle of the products, and by cooking and preserving our own foods, we can not only reduce our living costs, but also live more simply, and allow others in the world to simply live.

Cycling and Aquaponics

It is important that before adding plants and fish to your newly aquaponics setup that you start it cycling. No, I don’t mean go and ride your bike, but you need to establish the bridge between the fish and plants by establishing the bacteria.

Bacteria are the magic ingredient that converts unusable fish waste to plant fertiliser. The bacteria create a symbiotic eco-system without the problems that are found in aquaculture and hydroponics.

Cycling is the process that establishes the nitrogen cycle in the system. The nitrogen system is the ongoing process that converts ammonia produced by the fish into nitrates that the plans can consume.

Aquaponics Nitrogen Cycle
Aquaponics Nitrogen Cycle

Cycling starts when you add ammonia (NH3) from fish or other sources into the system. Ammonia is toxic and can quickly kill fish unless diluted or converted into another less toxic form of nitrogen. Ammonia is not readily used by plants, and must be converted by bacteria into a plant usable form.

Ammonia attracts a nitrifying bacteria called Nitrosomonas, that converts the ammonia into nitrites, which is even more toxic to fish. The presence of nitrites attract another nitrifying bacteria call Nitrospira, which convert the nitrites into nitrates which are the plant food needed.

It is important to regularly test the water in the aquaponics system to monitor ammonia, nitrite and nitrate, and pH levels, to ensure that they are kept in range.

You can start the cycling process using fish, but this is perhaps the most stressful option, as they can die. It is also possible to start the nitrifying process using liquid ammonia (pure ammonia or pure ammonium hydroxide), or humonia (pee-ponics). To start using these methods, add ammonia until the reading is 2-4ppm, and keep adding that amount daily until nitrite appears at over 0.5ppm. If the ammonia level goes over 6ppm, stop adding the ammonia, until back between 2-4ppm.

I think it is important to add plants to the system before starting cycling, as they can start using any nitrates in the system. My water in the system already had ammonia, nitrites and nitrates as I took it from my dam containing fish, ducks and yabbies.

Seasol, a seaweed based fertiliser available in Australia, is also an excellent way to start the cycling process. After adding the Seasol, and plants, check the ammonia, nitrite, nitrate and pH levels, wait 2 weeks, then fish can be added at a low density. More fish can be added once the system has stabilised and plant growth has started.

Plants and Aquaponics

Fish and plants are the main components of the aquaponics system. The growbed media provide the environment for the conversion of the ammonia produced by the fish, into nitrates that the plants need to grow. Your family consumes some of the plants, while some can be used to feed chickens or even back to the fish. The fish produced fertiliser can produce enough food to make a huge reduction in your weekly grocery bill.

So what plants can I grow successfully? The question ‘what doesn’t grow well’ will provide a much shorter list. The only plants in this latter list are those who do not like a pH much above or below a neutral 7.0, such as acid liking blueberries and azaleas, and alkaline preferring plants such as chrysanthemums, calendula, an zinneas.

Root crops will grow very well, but you may not recognise the final shapes, because it finds it difficult to expand in the growbed media.

Apart from these few exceptions, anything that can grown in soil can grow in aquaponics successfully. I am successfully growing rhubarb, strawberries, leeks, beetroot, salad greens, lettuce, cabbage, cauliflower, beans, tomatoes, coriander, parsley, kale, spinach, silver beet and more. I am limited by my seed library and food requirements.

I have broadcast beetroot, salad greens and lettuce seeds and they are successfully growing. I’ve had trouble with bean seeds rotting as they are too wet, so I’ve resorted to germinating on wet paper towel and then transplanting. This also works well for peas, melons and cucumbers. I like them to grow where I want them, not where they germinate, as placement is very important. I put the seeds on wet paper towelling, and place into a ziplock bag, checking them daily. Once the root is about 25mm, I gently plant them into the growbed media, with the root in wetting zone.

I have also bought seedlings and, after carefully washing the seed raising mix from the roots, planted them into the wetting zone of the growbed media.

In the future, I am planning to start seeds in vermiculite or worm castings or even grow plugs to reduce the costs of the plants. Some plants like bamboo and some natives that I grow in soil, can be very successfully started from cuttings inserted into the growbed media. With cuttings, do not use rooting hormones as it can affect the fish in the system.

Aquaponic Rules of Thumb

  • Avoid plants that prefer acidic or alkaline soil conditions.
  • Plants for aquaponics can be started in the same way for soil based gardening.

If the plants are looking unhealthy after a few months:

  • check your pH balance
  • insects

What do we mean by ‘sustainable’?

The dictionary provides lots of different definitions of this term. The meaning I am going to adopt is ” to supply with food and drink, or the necessities of life, as persons”. While this doesn’t match the meaning adopted by other authorities such as the United Nations, I think it defines my approach to sustainable living better.

While many businesses and organisations debate sustainability and how to define it, and the definition of “triple bottom line”, I am getting on with my approach to being sustainable living in providing food, shelter and energy to meet my life’s requirements.

Beyond the basic necessities (food, clothing and shelter) for sustaining our physical life, how much money and other possessions do we really need? These questions are often not investigated and pondered upon, but we spend our lives trading our time and skills for money. A life that is free and meaningful does not need the latest fashion or gadgets or expensive overseas holidays or the latest model car. Working long hours really doesn’t allow the time we need to look after our spiritual needs and for time to spend with family and friends – the things that make for an enjoyable life. Being rich is a state of mind, not a bank balance figure.

I’m not saying that money is not important – it is, up to a certain level. Once our basic needs are met, pursuing more money distracts us from the important things in life. It’s easy to become entangled in a consumerist society, and to think that consumerism provides freedom. Consumerism is destroying the very planet that we live on. Everything we consume is provided by our planet, and ultimately is returned back to it. Climate change and disappearing ecosystems are the indicators of our over consumption. How much longer can we persist with our consuming patterns before we go beyond the point of no return? Some scientists already think that we have gone beyond the tipping point with our production of carbon dioxide induced climate change. We need to remember past climatic climaxes that mean that all humans have come from an estimated 600 breeding pairs of homo sapiens. Is this going to happen again?

So what can we do? Are there alternatives? Much research is occurring in this area. Already research has shown that we are past peak oil production, but we are still not embracing renewable energy sources at the rate we should be. We are also at or past peak water consumption, with many countries populations experiencing water stress i.e. less water than they require each day to maintain a healthy life.

I think that we all have a responsibility to minimise our use of resources. Sure, I still have a phone, TV and many other ‘things’, but I am constantly reducing the ‘stuff’ that I have. I am building my own home from timber sourced from local native forests in a sustainable way, I have solar power with a backup diesel generator, a solar hot water system, chooks, and will soon add some cattle, as well as aquaponics providing fish and vegetables and an orchard (replanted this year, as most of our trees died off during the drought).

I am not self-sufficient by any means, but I am slowly requiring less resource inputs from

Twisted Savonius Wind Turbine
Twisted Savonius Wind Turbine

outside of my property. We use about 20l of diesel per month to cover our power requirements from the backup generator each month. When it is overcast, solar cells do not work very well, and I only have enough battery capacity for about 3 days. I will be making some vertical wind turbines to reduce our diesel requirements.

We harvest all of our water from rain – some stored in dams for the gardens, orchard and aquaponics (doesn’t use very much), with household water for drinking, washing, cooking and showering coming from a 27,500 litre tank. Once I have the verandahs on the house completed, I intend to install a 250,000 litre tank to store the water from a combined catchment of 350 square metres. Each millimetre of rain provides 1 litre of water per square metre of roof area (350 square metres by 660 mm = 231,000).

Future posts are going to expand on what we can do and what I am doing in particular to reduce my impact on the planet’s resources.