PUBLISHED IN THE RENO GAZETTE-JOURNAL
By Ashley Andrews and Heidi Kratsch
In recent years, the quest for sustainable food production unearthed a new way to grow edible crops. Those who use this new method reap crops that mature twice as fast and use less than one tenth of the water than those who sow using more traditional food production methods. And, this increasingly-popular technique is scalable—meaning it can be used at home to grow a countertop herb garden and it can be used on a large scale to produce fruits, vegetables and herbs for market. To a state suffering from prolonged and severe drought, the idea of gardening and farming on any scale with 90% less water sounds too good to be true, but it is not. There is a catch, however—fish!
This novel growing method, called aquaponics, combines aquaculture, or the cultivation of fish for food, with hydroponics. Hydroponics involves growing plants without soil. The union of aquaculture and hydroponics is a match made in heaven because they each are not sustainable on their own. Aquaculture produces fish waste, and hydroponics requires fertilizers. When combined, however, the plants act as biofilters for the fish and fish waste is used by the plants as fertilizer. Aquaponic growers can then harvest sustainably cultivated produce and fish.
To get started with aquaponics, growers must first select a system to use. There are many types to choose from, and they can be purchased commercially or hand-crafted. Options range from an indoor system featuring an aquarium and simple grow bed to solar-powered outdoor systems operated inside greenhouses or hoop houses. In northern Nevada, indoor or greenhouse-based systems are a grower’s best bet. They protect fish from our winter weather, which can be severe, depending on the year and microclimate associated with the location of the system.
The easiest way to grow aquaponically is to place fish and plants in separate containers and connect them with plumbing to recirculate water from the fish to the plants and back again. In this simple set up, plants grown in a coarse soilless medium, such as gravel or expanded shale, are flooded periodically with used water from the fish tank. Beneficial bacteria build up naturally in the system and convert the fish waste in the water into plant food. Composting worms can be added to the growing medium in ebb-and-flood systems like this one to help the bacteria along in this process. Once the plants filter out the nutrients natural bacteria and worms derive from fish waste, the now re-oxygenated and clean water is recirculated back to the fish tank.
Aquaponic fish tanks are most commonly stocked with tilapia, trout, arctic char, bass and some species of perch and catfish. For information on the possession and importation of wildlife, like fish, and to obtain an annual permit to raise fish, contact the Nevada Department of Wildlife. To learn more about growing fish and produce together, attend Cooperative Extension’s Grow Your Own, Nevada! Aquaponics class held 6-8 p.m. on Sept. 15 live in Reno at 4955 Energy Way and via videoconference statewide.
Ashley Andrews is the Horticulture Assistant and Heidi Kratsch is the Horticulture Specialist with University of Nevada Cooperative Extension. Have plant questions? Contact a master gardener at 775-336-0265 or firstname.lastname@example.org, or visit www.growyourownnevada.com. For information on drought, visitwww.livingwithdrought.com.