Aquaponics = aquaculture (the raising of edible fish) + hydroponics (growing vegetables and herbs without soil). You may have seen examples of this revolutionary way of growing food in some of the projects featured on Inhabitat. Per square foot, it’s the most productive form of agriculture on the planet, and is a perfect example of a living machine: a self-sufficient assembly of plants and animals that functions like an ecosystem, producing food for people without creating waste products or pollution.
If you’re inspired to try out an aquaponic system instead of a vegetable garden in your backyard this summer, this guide will serve as an overview, giving you all the information necessary to get started. It’s a bit more involved than a typical vegetable garden, but anyone with a little mechanical ingenuity and determination can make it happen. If you feel timid, we suggest starting small to refine your technique before scaling up to a system that can feed the family (if not the neighborhood).
Every aquaponic system will include the components listed below. There are many options to add on to these and customize the system, depending on your particular circumstances and goals. For example, most people in cold climates will opt to build their aquaponics system in a greenhouse to keep it going year-round.
Image via Milkwood, on Flickr Creative Commons
In theory, a well-tuned aquaponics system can support one pound of fish per gallon of water. When starting out, however, it’s better to plan on stocking one fish for every 10 gallons of water to make sure the system doesn’t fall out of balance (plus the fish will have more space in which to swim).
Most do-it-yourselfers start with either a 55-gallon barrel or a 225-gallon square bin; two standard sizes of food-grade tanks that are fairly easy to come by recycled from the food industry. Just make sure they were used to hold benign things like soy sauce, rather than something toxic that might have left a residue. Aboveground vinyl swimming pools are the top DIY choice for larger tanks.
Image via Wikimedia Creative Commons
Your vegetables will need some type of water-resistant container to house the soilless medium that they’ll be grown in. There are many products available for this purpose, but there are just as many DIY approaches. The simplest route is to build shallow wooden boxes (6 to 10 inches deep), just like ordinary raised beds for vegetables, and line them with pond liner.
Each bed is then filled with an inert growing medium, such as perlite (which is super light, allowing the beds to be elevated off the ground) or fine gravel from your local landscape supplier (inexpensive, but heavy). Coco coir is the fanciest growing medium available and is often used by professionals for its ability to retain air and moisture simultaneously. A mixture of equal parts of all three products is actually a great formula to try.
You can plan to ferti-gate a growing area up to 10 times the surface are of your fish tank.