Starting With Aquaponics

Growing up on a dairy farm meant that we always had fresh milk, and Grandma used to have a wonderful vegetable garden using aged cow manure as a fertilizer and soil conditioner.

Fast forward nearly 50 years, and I now live a long way from the dairy farm, in a fairly arid area. When we moved onto the bush block, I tried gardening using traditional methods. Sure, I managed to grow some herbs, and salads, but that was all. The tree roots would rob the plants of moisture, and so after a couple of years changed. I made a tunnel using reinforcing mesh and 50% shade cloth. The garden beds were lined with builders plastic and filled with aged cow manure and soil. It worked very well, producing good quantities of vegetables and herbs year round. I even managed to have tomatoes and bell peppers survive over winter with our heavy frosts.

Aquaponics NFT System
Aquaponics NFT System

It took about 3 years and the tree roots penetrated the plastic garden bed liners, and production dropped dramatically as the trees stole the moisture. While living and working in Alice Springs, we stayed with friends who had created an aquaponics system using recycled bath tubs and spas, with 200 silver perch. It worked very well, and provided a lot of herbs and vegetables for everyone staying there.

I have tried hydroponics before. It worked well, but I had to keep buying the minerals and fertilizer mix, as well as dumping the water every so often. I considered the dumping of the water a huge waste, especially here, were we get 600mm annual rainfall and 2.5m of evaporation.

I’ve tried aquaculture, but because I never had a large, continually flowing source of water, could never stock the fish densely enough to make it worthwhile. Also, the water had to be dumped occasionally.

With aquaponics – a combination of aquaculture and hydroponics, the media in the growing beds act as a biological filter for the fish. To me, it is the best of both worlds, and I get fresh fish as well as vegetables.. According to research, it takes only 10% of the water to grow the same amount of vegetables as would grow in soil.

Commercial Raft Tank
Commercial Raft Tank

There are many different ways to set up an aquaponics system, ranging from small fish tank size with one or two small growbeds suitable for the balcony or the edge of the patio, to full grown commercial systems producing tonnes of fish and vegetables. A cheap way of getting started, that works well is to use IBCs – International Bulk Containers – of 1000l capacity. As long as the ones used have not contained chemicals, they can be cleaned and used. For more information about many different ways of using these containers, visit and download the free IBC of Aquaponics publication from http://www.backyardaquaponics.com/Travis/IBCofAquaponics1.pdf. There are also many YouTube videos available to view to see how the systems work.

My IBC based aquaponics
My IBC based aquaponics

After about 6 months of research and design, I started getting mine established. I was given 6 IBCs, and I had a couple that I used to use for water carting. My system is referred to as a CHOP2 system – that is the sump tank pump is below the growbeds, and pumps about 80% of the water through the grow beds, and about 20% through the fish tank. The fish produce ammonia, which the bacteria in the grow bed media convert to nitrites and eventually to nitrates which the plants can use.

Food

Oxfam has stated that for the sixth time in the last 11 years, the world is going to consume more food than it produces. This is caused by unusual weather conditions in the USA, Russia, and other major food exporting countries. It is estimated that staple food prices will double in the next 20 years, which will be disasterous for poor people around the world.

So, you wonder, what does this have to do with you? For starters, more of your income is going to go to paying for the food you and your family need to survive. More people are going to be hungry, and get more diseases, and more people will die because of malnutrition (especially children, who are most susceptible).

What can you do? Well, you can do a number of things.

  1. You could start a small garden at your home on your balconey or in your yard or on the road verge.
  2. You could join or start a community garden program.
  3. You could shop at your local farmers market, which in turn encourages them to grow more food and sell locally.
  4. You could contact a local farmer and buy direct from them or even form a cooperative with others to do the same.
  5. If you have the room, you could start your own aquaponics project. From the space of a single car carport, you should be able to produce enough food to feed 4 people.

 

Mudbricks and Building

Why has earth-wall construction been so little used in past years? The answer is that as there is nothing to sell there are few to extol its merits. G.F. Middleton, Earth Wall Construction 1952.

Timbuktu Mosque made from mudbricks
Timbuktu Mosque made from mudbricks

For centuries, earth and water have been used for construction in Africa, Asia and the Americas. It is estimated that around 20% of all the buildings on the planet are build from earth. Earth is very little used in Australia. It is strong, durable and well suited to the Australian climate. It does have problems meeting the energy ratings as required for new buildings, but after having lived in mud brick homes and 5-star energy rated homes in cold climates, I know which one I prefer, as do many other people.

Earth walls are fireproof, cheap (requiring labour and minimal mechanical inputs), dry and hygienic. It exists at every building site, and many times is carted away. The walls are cool in summer and warm in winter, and white ants and insects (other than mud wasps, which collect pest insects anyway) don’t tunnel in the walls.

Muscle power and water are essential ingredients, along with the sun to dry them. The first buildings in Australia in Sydney were wattle (thin sticks) and daub (mud) mixed with straw. Many of the villages in Africa and South America are still built using this ancient method.

Today, most earth walls are built from rammed earth (pise) or unfired mudbricks (which I have used). Pise is made by putting damp soil into a movable framework and ramming it. It was introduced into Normandy by the Romans, and spread from there. It is still widely used in China and other Asian countries.

Mudbricks have been used for well over 8000 years to build shelters in hot, dry, arid

mudbrick making
Mudbrick mold showing some bricks just made

countries in the Middle East, Africa, China, Mexico and South America. Mud is placed into a bottomless mould to make blocks, which are then allowed to dry, and then stacked near where they are to be used.

When I started building, I had lots of time, not much muscle power, no mechanical power, some water and lots of dirt. I had helped my daughter made some mudbricks as well as putting them into walls. It is a bit hard on the back, and hands. We used an old bathtub for mixing. We would make a batch in the morning, mix and let soak all day, then make the bricks in the afternoon, and then make another mix, so that it would ready for putting out the following morning. This method gave

mudbricks drying, waitiug to be stacked
Mudbricks drying, waiting to be stacked

us 60 bricks or so per day. Doesn’t seem like many, but after 10 days, we had over 600, which was enough for the small cottage. I have used the same method here, sometimes doing 3 mixes in a day giving close to 100 bricks per day without much effort.

Slowly but surely the house walls are coming along. I put up 4 courses, then some building strapping for ensuring the wall is solid and fastened to the log poles holding the roof down, then another 4 courses. This is enough for the day, otherwise the mud mortar gets squeezed out by the weight of the bricks. I get to work in the shade most of the time, which suits my skin.

mudbricks stacked near wall ready to use
mudbricks stacked near wall ready to use

The house is not yet finished – a work in progress, but at current rate, will be airtight and warm for next winter, with about 1000 bricks still to make. Once the house is finished, we are planning on making a couple of 2 bedroom units and another 4 bedroom cottage for people to stay in. The idea is that they work 4-6 hours per day in order to pay for accommodation and their food from the aquaponics system.

mudbrick wall waiting for shaping of half-bricks
Mudbrick wall waiting for shaping of half-bricks

There are many people who for circumstances beyond their control, are unable to find somewhere to live that is affordable. Towns and cities are not good places for lots of people, and this is provide some alternative for a few people while they get their lives back together with the assistance of counselling, art therapy, and meditation.

mudbrick wall at eight courses high
Mudbrick wall at eight courses high

 

Geraldton Wax

Geraldton Wax is a flowering shrub with white or pink flowers that comes from Western Australia. It is very similar to Tea Tree and the flowers last a long time, making it very popular in the cut flower trade.

This plant is supposed to be frost tender – the temperatures go down to -6C here. Without any care over the last 3 years, it has survived and this is the 2012 flowering – absolutely magnificent (well, in my opinion). There aren’t many local shrubs that can match it. It loves sandy soil in moderate to full sun, and will withstand dry periods, making it perfect for growing in my local climate. It is short-lived in high humidity areas, like along the east coast of Australia.

Geraldton Wax Flowering 2012
Geraldton Wax Flowering 2012
native bee coming in for nectar on Geraldton Wax flower
Native bee coming in for nectar

Many of my neighbours have tried growing these without success. Their properties are lower down, and receive heavier, longer frosts that I do.

Next year, I intend to plant many more these to provide extra food for the insects and birds. Since moving to this place, our plantings of calistemons  and grevilleas has increased the bird population as well as our local native stingless bees, as they now have food when the local natives are not flowering. We are surrounded by native forest, so all we are doing is supplementing their diets.

Extra Nutrients for Aquaponics

I started off my aquaponics with Seasol fertilizer. I currently don’t have any fish in the system, as I have not been able to source any (the hatcheries are all sold out). I’ve been running on a pure source of ammonia, checking levels daily.

Some of the newly emerging leaves have yellow edges. Normally the waste from the fish provides the ammonia and other nutrients required. Sometimes potassium and iron can be lacking, which can result in leaf yellowing.

Some web sites suggest adding a few rusty nails along with seaweed extract. I have added the seaweed extract, as well as some iron chelate mixture. This has solved the problem.

My Gardening

When we first moved to this property, I tried to garden using traditional methods i.e. growing plants in soil. Not very successful. I could not keep water up to the plants. The annual rainfall here is 600mm, but we have 2.5m annual evaporation, so their is a large water deficiency.

I then tried raised garden beds with building plastic underneath to try and stop the tree roots stealing the water. Much better production, but after a couple of years, the roots worked their way into the beds.

I tried growing in containers, but that meant watering at least once per day. I tried hydroponics, but was not happy dumping the water every so often due to the build up of salts and minerals. Aquaculture did not produce the food we needed, and obtaining a licence is an expensive exercise.

While working in Alice Springs, we stayed on a property where the owner had made use of old bath tubs and a lined garden pond to create an aquaponics system. He had about 200 silver perch fingerlings in the pond and an old spa bath, with about 20 old bath tubs. The production of vegetables was amazing.

I started reading and learning all I could about this system of plant production, as I thought that it might solve many of the issues that I have here. We are on a similar latitude to Alice Springs, and have a similar climate, with frosts over winter and hot days during summer, and raining whenever it happens (no real set pattern).

Musings from a wandering sage

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