Eating a mainly “whole-food, plant based” diet is not only good for your health but also good for the planet as it takes far less resources (water, food, land and energy) to produce edible plants as it does to produce edible animals.
Even so, the way that food crops are usually produced (using huge amounts of chemical fertilizers, insecticides and energy in a monoculture system) and then distributing far afield, is also highly inefficient, energy intensive and damaging to the ecosystem.
One way around this is to farm foods locally in what is called “Edible Forest Gardens” (both plants and animals in a mutually beneficial system) using Permaculture principles.
“An Edible Forest Garden is a perennial polyculture of multipurpose plants. Most plants regrow every year without replanting: perennials. Many species grow together: a polyculture. Each plant contributes to the success of the whole by fulfilling many functions: multipurpose. In other words, a forest garden is an edible ecosystem, a consciously designed community of mutually beneficial plants and animals intended for human food production.” (quote from Edible Forest Gardens, Vol 1, by Dave Jacke with Eric Toensmeier)
Another way (which is the way I have decided to go) is to use Aquaponics to grow organic fruit, nuts, vegetables and fish in my own back garden in a sustainable low energy and low water system for myself, friends and neighbours.
So what is Aquaponics?
Aquaponics is an integrated aquaculture (growing fish) and hydroponic (growing soilless plants) system that mutually benefits both environments. Aquaponics uses no chemicals, requires one tenth or 10% of the water needed for field plant production and only a fraction of the water that is used for fish culture.
The waste from the fish tank is converted first to nitrite and then to nitrate by naturally occurring bacteria in the grow beds which is then used as food by the plants. The only external input to the system is food for the fish.
Both systems complement each other as a single unit, not as separate units.
Once the system is initialized the water stays Ph balanced and remains crystal clear. The water is recycled with a small amount of water added weekly to compensate for what is lost by evaporation and transpiration by the vegetables.
The fish produce waste (mainly ammonia) which is continually pumped out of the fish tank into the grow beds where the naturally occurring bacteria convert the Ammonia first to Nitrite then to Nitrate. The grow beds are filled with 20mm gravel, which is the growing media, and effectively filter the water of fish waste before draining into the sump tank. Here, the single pump, pumps the clean water back into the fish tank. This is called a CHOP (Constant Height, One Pump) system.
My system will be housed in a 6 meter by 7 meter greenhouse and be comprised of a 2300 liter fish tank, 6 grow beds, a fingerling tank and seedling propagation area. Water from the roof of the greenhouse will be captured by a water and be used to top up the fish tank. Electricity will be supplied from my house by way of my 5kw solar panel array, effectively making the whole system completely sustainable.
Food for the fish will be largely grown on site (Maggots, Worms and Duck Weed).
As the system will be completely enclosed in a controlled environment I expect to extend the growing season for all plants and thus maximize diversity and variety throughout the year.
The system, once matured, should produce enough food for many families and is intended to make enough money to be self-sufficient and be used as an educational facility as a way of encouraging others to set up similar systems.
I expect to stock the fish tank with fingerlings and start growing by May/June 2013.
I will post all developments as they arise and share my learning curve with you, the good, the bad and the ugly.
See follow up postings
Aquaponics update 28/12/2012