Unless you are Alice Waters or Barbara Kingsolver, planting and maintaining an edible garden can seem a tad arduous. In her book "Animal, Vegetable, Miracle," Kingsolver extolled the pleasures of home-grown food, but all the soil amending, weeding and watering - not to mention controlling greedy pests - takes time, effort and, of course, space.

Enter aquaponics, a system of food gardening that has a small but growing fan base, not least because its advantages seem almost too good to be true. An aquaponics installation requires no soil, scant water (2 to 10 percent of what is used in the average vegetable garden), a modest financial outlay and minimal maintenance. There's no dealing with pesticides, and the system is sustainable and easy to set up. For gardeners conscious of the need to slash their water use during California's drought, or those with little or no land, this method has a lot to offer.

The cherry on top is that you get to enjoy nurturing a school of pretty fish. Fish can be fed with regular fish food or, eventually, with the fruits of your crop, creating a virtuous circle in which you know precisely what is going into the food you eat. Whether you consider your fish a decorative feature or dinner is up to you.

"My wife and I were blown away when we saw aquaponics for the first time," says Bob Rudorf, who has a system installed under a grow light in the living room of his Sonoma home and is harvesting baby lettuces and culinary herbs.

Aquaponics combines hydroponics, or water-based planting, with aquaculture, or fish cultivation. The idea is simple: In a closed-loop system, water from a tank full of fish, rich with fish waste, irrigates and feeds plants that grow in a bed of gravel. The plants filter the water, which is then channeled back into the fish tank. The boxed plant bed is typically set at table height to distance it from soil-borne diseases such as the fungi that grow on tomatoes, but there's another benefit: no need to bend or kneel to tend your plants. Aquatic life can range from goldfish, trout and tilapia to crustacea, frogs and turtles; a simple pump is required to circulate the water. Plants can be grown from seed or as transplants that have been cleaned of soil.

Sustainability in action

Rudorf and his wife, Amelia Belle, discovered aquaponics at the San Francisco Green Festival last fall. Strolling past the exhibits, the couple were disappointed with how little they saw that was truly green. "It screamed commercialism," Rudorf says. "There were lots of purses made out of recycled candy wrappers." On an upper level they came upon Oakland aquaponics company Kijiji Grows. "There were these beautiful gardens and blooming flowers," recalls Rudorf, who decided this was sustainability in action.

Kijiji Grows was started last March by Keba Konte, co-owner of the Guerilla Cafe in north Berkeley, and Eric Maundu, who trained in computer science and industrial robotics. "An aquaponic garden is just one big robot," he says. The company has worked extensively with children, setting up aquaponic gardens in half a dozen schools and several preschools in Oakland. Maundu says kids are naturally drawn to the simplicity of the gardens and the transparency of how they work.

"Just like with recycling and other sustainable concepts, it's the kids who are initially energized by the idea, and they pass their enthusiasm on to their parents," he says.

Kijiji, the Swahili word for village, has also collaborated with Oakland's Office of Parks and Recreation to create a community garden in Mosswood Park, at the corner of Macarthur Boulevard and Webster Street. In March, their three tabletop beds, one of which uses solar power for its water pump, are bursting with chard, mint, parsley, bok choy and broccoli. The gentle gurgling of the water making its way from the darting goldfish in their black tub to the plants above makes for a soothing aural backdrop.

'Rains all the time'

Nearby, a number of traditional raised beds tended by neighbors also look abundant, but come the summer months they will require constant irrigation. As Maundu puts it, with aquaponics, "it rains all the time."

Aquaponic gardens are not as tied to the seasons because they are not tied to the ground. "You can push spring and summer much longer," Maundu says.

Konte and Maundu bring adults and children to the park to teach them how to create and maintain aquaponic systems. The majority of plants lend themselves to aquaponics, including leafy greens and fruiting and flowering plants. Tuber crops, such as potatoes, are one exception. In the tanks at Mosswood, Kijiji likes to stock goldfish: "Some of the younger children find the whiskered catfish scary," Maundu says.

Ideal for the poor

Aquaponic systems are ideal for poor communities, here or in developing countries, because they don't require fertile land, significant water or funding, and in some places families can rely on them for subsistence. Maundu has helped set up installations in Kenya for families who have lost adults to AIDS. In these instances, it is often the family members left behind - children and grandparents - who benefit from a simple aquaponics garden.

"There, it can be a matter of life and death," Maundu says. It helps that the systems can be built from whatever materials are available locally, be it coconut fibers, rocks, bamboo or wood.

Inka Biospheric Systems, a San Francisco company that produces a variety of aquaponic installations, is looking at how it might provide systems to earthquake-devastated Haiti. Founder Paul Giacomantonio, who started out as a stonemason building fishponds, among other things, and who has worked in Gabon, Senegal and Zimbabwe, says he sees Inka's "micro farms" as part of an effort to ease poverty.

Inka has created aquaponic gardens at Sanchez Elementary School in San Francisco's Mission District, and has installed a suspended version of its rotating cylinder garden on the Plastiki, the sailing vessel made of recycled plastic bottles that David de Rothschild intends to sail across the Pacific from San Francisco this year. The garden is clamped onto the vessel's mizzenmast, and the cylinder is enclosed in a clear covering to create a greenhouse effect and to keep saltwater off the plants.

Inka also has developed a bio-quilt in which seedlings are grown to create vertical walls of plants sustained by water from a fish tank. These are suitable for condo and apartment patios or decks, Giacomantonio says.

In Sonoma, Rudorf is hoping that aquaponic gardens like his may one day be in every public school in the county. "There's a commitment to put gardens in schools, and it makes sense for them to be aquaponic," he says. In the meantime, he says his family is deriving a lot of pleasure from their small indoor installation. "It has a function and it is really pretty. And we love just looking at the fish."