Aquaponics systems have become more and more popular over the last few years, and there’s no surprise why.
This method of growing food is completely organic; it uses the fishes waste to grow the plants as well as having numerous other benefits. It reduces the amount of water needed to growing plants in comparison to other traditional gardening methods and it’s a completely self-sustaining closed-loop system.
Aquaponics is the combination of aquaculture, growing fish to harvest, and hydroponics, growing food without soil.
These systems can be anything from tiny counter-top kitchen systems to grow herbs, to larger community set ups which can provide fruit and vegetables for whole communities.
We’re going to take a look at what you need to set up a community aquaponics system and the different types of plants you can grow in a community set up.
1. The Pond
When you’re creating a community setup, you’re probably going to need a few large aquaponics systems; these will all require large houses for the fish.
Some examples of containers you can use include barrels, bath tubs, large food grade containers, plastic containers, or anything else as long as you use a waterproof liner.
The example we are following uses a simple plastic container as the pond. The larger the pond, the more fish you’ll be able to keep and the more plants you’ll be able to grow.
2. The Grow Bed
The grow bed is where you’ll grow your plants so it will need to be large enough to grow the amount of plant you want to grow.
The recommended ratio for pond to grow-bed for people who are just starting out is 1:1. Again, you can use any container as long as it is water-tight.
Using food grade containers are both cheap and a good way to recycle materials.
You’ll hear a lot of people say that a grow bed needs to be a certain depth, we haven’t seen any evidence to suggest that this is the case and have seen food being grow successfully in 6 inch deep beds and 14 inch deep grow beds.
Most grow beds sit above the pond, but with a larger community set up you may want to have a few grow beds surrounding one large pond. You can either sit in straight on the floor (as long as the floor is level) or you could build a stand to sit the bed above the tank as in our example.
Once the grow bed is built, you’ll need to add a grow media. The grow media replaces the need for soil and there are a few different choices available.
The most popular choice is clay pebbles. They are smooth and provide an excellent surface for roots to grow into easily. They are also pH neutral so won’t affect your water supply.
3. The Equipment
In addition to the pond and the grow bed, you’ll need a water pump, a siphon and possibly a sump tank depending on the size of your aquarium.
The water pump is arguably the most important part of your aquaponics setup. The size will depend on the size of your pond and how many grow beds you have. Its purpose is to pump the water from the pond to the grow bed.
The siphon is used to drain the aquaponics system in ebb and flow setups, the most popular one to use is a bell siphon. A bell siphon works by flooding the roots with hydration and nutrients, and then draining the water to oxygenate them.
You’ll need a sump tank if the water volume is greater or equal to the volume of your grow beds. A sump allows the fish tank water to remain constant regardless of how empty or full the grow beds are with water. The sump is a container where the water collects in between being transferred to either the pond or the grow bed. It sits below the grow bed.
4. Add the Fish and Plants
The most common fish to use in an aquaponics set up are Tilapia, other common fish to use are ornamental fish such as Goldfish and Koi.
There are over 150 plants that have been successfully grown in aquaponics setups so far. The most popular and easy to grow plants are leafy greens, as well as tomatoes, peppers and cucumbers.
Vegetables that would work well in a new system are those that don’t have very high nutrient demands such as:
• Salad rocket
Other plants with medium nutrient demands are fine to grow in aquaponics systems too. These include:
There have also been successes of growing some high-nutrient demanding plants such as:
Community aquaponics systems can provide so many opportunities for local people, both in volunteer and job roles. This method of growing plants provides locally grown, organic food and because no soil is required, systems can be setup in old warehouses, or greenhouses – it doesn’t matter on the quality and the nutritional value of the land.
Robert Woods is the editor of Fish Keeping World: www.fishkeepingworld.com
Watch: Greenhouse aquaponics