Instead of swimming around aimlessly, your goldfish could help your garden grow.

RODALE NEWS, EMMAUS, PA—Looking to produced more of your own food? While you may not have enough square footage for dairy cattle or even a chicken coop, you probably have the space, either indoors or out, for a fish tank or fish pond. If so, you're halfway to an aquaponic garden, which allows you to grow animals and vegetables in one harmonious ecosystem.

THE DETAILS: Aquaponics is a type of farming that combines hydroponics, or growing plants in water, with aquaculture, or fish farming. With hydroponics, plants must be fertilized with a chemical solution, which is why the USDA has yet to certify any hydroponic farms as organic. As for aquaculture, one of its biggest drawbacks is that all the nutrient-rich fish waste in fish ponds has to go somewhere, lest it poison the fish. The perfect solution? Aquaponics, which allows gardeners and farmers to use fish waste—rather than chemicals—to fertilize their waterborne plants.

It's essentially an organic way to feed a hydroponic garden, says David Epstein, president and CEO of Earth Solutions Inc., a company that makes home-based aquaponic systems. "Nature works best when we work less," he says. "People have taken what's natural—the normal ebb-and-flow tide of rivers and lakes that naturally fertilizes the shoreline—and artificially divided it into hydroponics and aquaculture. In trying to maximize efficiency, people ended up increasing the labor involved." With aquaponics, the only real labor is feeding the fish and harvesting your crops. The ecosystem takes care of the rest.

Keep reading to learn how you can build an aquaponic garden at home.