For the next several weeks my articles would be targeting the topic of food self-sufficiency and production. The Food Self Sufficiency series will start with aquaponics, the ultimate solution to at-home backyard food production. The smartest way to generate more food per square foot than a backyard garden alone. Aquaponics is the most space-efficient way to generate healthy calories to support you and your family today.
Depending on where you live, it can also be expensive. Sure, a half-acre “urban farm” can produce a lot of food, but they’re hard to find in most places. Not to mention, the cost of time. The amount of maintenance of such a massive operation is a commitment few people can manage.
So, is food sufficiency just a survivalist dream? Could I produce enough calories to survive in the space of a backyard?
It is a production system that couples aquaculture (raising aquatic animals such as fish, crayfish, snails or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment whereby the nutrient rich aquaculture water is fed to hydroponic grown plant, involving nitrifying bacteria or converting ammonia into nitrates.
Aquaponics is a nearly closed ecosystem. One where fish and plants are mutually beneficial to each other. Combination and interdependence of two ecosystems:
Aquaculture (raising edible fish and other seafood)
The plants use fish waste as nutrients while the plants remove the fish waste from the water. So the fish feed the plants and the plants filter the toxins from the water. When in balance, the amount of fish waste produced is offset by the plant’s ability to use it. Here’s a simple overview of this system in action:
1 – Ammonia Is Added To Water Via Fish Wastes
2 – Water With Ammonia Is Pumped To Plant/Bacteria Containers
3 – Bacteria Converts Ammonia Into Nitrate (plant food).
4 – Nitrate Is Absorbed By The Plants
5 – Clean Water Is Returned To Fish Tank
First off, using aquaponics means eliminating the need for unnatural chemical fertilizers. They become unnecessary, unlike traditional hydroponic systems. By being soil-free farming, complexities of compost management associated with regular gardening can be avoided.
This can be a game-changer if you have poor or contaminated soil –or even no soil at all! This means you get a lot fewer weeds in your garden and the ones you do get are easy to remove by the root!
Aquaponics is efficient. It’s the best way to produce lots of food in a small footprint. And it’s expandable. Making it perfect for growing more and more self-sufficient over time. With an indoor light source, you can set one up inside; away from the weather, pests, and prying eyes.
The simplest aquaponic systems grow plants above the fish on floating mats. This means you only need space for a small fish tank and a limited amount of pumps or plumbing to get started. Such a compact setup makes home aquaponics ideal for limited spaces.
Finally, aquaponic systems produce both nutritious vegetables and protein. The perfect combination for a basic meal?
This is hard to do with a hydroponic system alone. Why? Because most vegetable proteins (i.e., beans) need a lot of nutrients and space. With aquaponics, the fish are your source of protein. And as we all know, fish is one of the healthiest sources of protein.
Science Behind Aquaponics
Fish release ammonia as a waste product. It comes from their gills and fish waste. In a closed system, if it’s not removed, this ammonia will build to toxic levels. And the more fish you have, the faster this build-up occurs. But aquaponics puts this natural “toxicity” to good use. It turns ammonia into plant food using two types of bacteria. Both in the form of biological filtration systems.
The first bacteria (Nitrosomonas) consumes ammonia and releases nitrite. Following that, second bacteria (Nitrobacteria) converts the nitrite to nitrate. Finally, plants use nitrates as their primary nutrient. This process cleans the water and keeps it healthy for the fish.
Planning of an Aquaponics System
One of the benefits of aquaponics systems is they are easily scalable. If you find yourself short on fish or vegetables, you can add another tank or increase the size of your current one. If you are overrun with food, you can harvest an entire tank setup. Freeze or can the surplus produce and scale down your system accordingly.
This is why IBC (intermediate bulk containers) are popular tanks for aquaponics. These are easy to find and often have plumbing fittings already in place. The standard shape is a simple cube design. It also has an integrated pallet base which makes the system sturdy and easier to move than other tanks.
Choice of Plant and Fish
You’ll need to get the organic components of your system – the fish, plants, and bacteria. But which fish and plants can form the ecosystem?
Bacteria are straightforward – it’s the same variety for all water temperatures. But the choice of plant and fish are temperature dependent. They must be hardy enough to tolerate the environmental conditions (i.e., the temperature swings).
So keep in mind the temperatures at which the plants and fish will live year-round. This is especially true if you’re planning an outdoor system in winter climates. Here are some basic water temperature guidelines for fish and plant selection:
Warm Water Tanks
With warm water tanks choose a fish species that can survive on low amounts of dissolved oxygen. Tilapia, channel catfish, and yellow perch are good options. Tilapia has the added benefit of quick reproduction and mild flavor.
Channel catfish also have rapid growth characteristics. But you must remove their scale-free skin before cooking. They don’t tolerate excessive handling very well. Yellow perch are aggressive feeders and reproduce fast as well. They also taste great and are easy for beginners to manage.
With warm water systems, consider leafy warm-weather greens. Varieties such as lettuce, peas, and basil are best. These vegetables all do well with warm water tanks and produce a quick harvest.
Cold Water Tanks
In colder water, many of the same fish species will work. But perch is temperature tolerant, as are channel catfish. Trout are best left for more established aquaponics systems. They are ideal once you’ve mastered a stable, highly oxygenated water system. That’s because trout are more sensitive to water chemistry fluctuations.
Alongside cold-water fish, thick leafy vegetables are best. Kale, spinach, bok, choy, and swiss chard all tolerate or thrive in colder climates.