If you have a courtyard that could do with a makeover, here’s an idea: grow your own food by setting up an aquaponics DIY system, as Carmen Brunette and François Zinserling of Everton in KZN have done.
Words and images by Andrea Abbot
What is aquaponics?
Aquaponics entails water being constantly recycled between fish and plants, so that fish waste provides nutrients for plants, and the plants, in absorbing those nutrients, purify the water for the fish. It’s a win-win situation that produces high quality veggies and fruit, and, if you’re so inclined, fresh fish too.
How to build an aquaponics system?
“It’s easy to set up a system like ours,” Carmen says. “You need a lovely sunny spot, a pond for the fish, and basins in which you will be growing your vegetables. You also need a pump, some pipes and connectors. We used perlite (a type of gravel) in the basins as our growing medium and obviously you need fish – any freshwater fish will do – and plants. Connect everything so that the water from the pond flows through the grow medium and back into the pond.”
Francois designed and built the system so that water is constantly gravity fed from the fish pond into a trough below a sort of scaffold rigged up against a wall and which supports several tiers of containers. In these containers plants like spinach, beans, broccoli, strawberries and cucumbers grow happily side by side.
From the trough, the water is pumped to the top tier and it then filters down through all the basins and back into the trough from where it’s pumped back to the fish. It’s a great way of maximising a limited space and of repurposing a courtyard and a bare wall.
“Ours is a very simple system,” says Carmen, “and we can’t grow everything in it. We found that tomatoes and the squash family didn’t do well. So if you go for a basic system like ours and also want to grow other types of vegetables you still need a vegetable garden.”
Nevertheless, Carmen is always experimenting. “I recently started re-growing vegetables from kitchen scraps and the onions are doing very well. I also use the aquaponics to germinate seeds and to root cuttings.”
The beauty of an aquaponics DIY system is that it requires minimal maintenance. “Sometimes a pipe might get blocked but it takes a few seconds to unblock it. Even if a pipe is blocked the plants can survive for a number of days because the growing medium remains moist for a good while. You also need to check for water loss because occasionally a connection might spring a leak.”
Once every three months, Carmen does a partial water change when she siphons the bottom of the pond. That water is then used for the garden or pot plants. Other than that, plant basins are cleaned and the perlite replaced every two years. “If you weigh that up against never having to water your plants and never having to weed your beds, this is the least labour intensive way to grow vegetables.”
Pesticides are taboo. “Once we had an aphid infestation. I planted marigold which seemed to sort out the problem. Occasionally I have an adventurous slug but since I’ve allowed the guttural toads to move in, the slugs usually get eaten before they reach the plant basins.”
Advice for people wanting to set up their own system? “You need to know how to keep fish healthy. When you get to know your fish, you quickly notice when something is bothering them. Other than that just experiment with plants to see what grows.”