MONTELLO — Rebecca Nelson and John Pade have one simple goal as their company grows and moves to a new facility along Highway 23: They want to feed the world.
They don't plan to do that with anything they grow in their greenhouses. It's through the development, education and selling of products for aquaponics that their company — Nelson and Pade Inc. — seeks to make a difference in the way people grow or acquire food.
Aquaponics is the combination of two practices: aquaculture (fish farming) and hydroponics (growing plants without soil). Fish waste provides the nutrients the plants need, all in one integrated system.
"We're trying to reinvent the 21st century family farm and make it profitable," Pade said.
In a greenhouse where Nelson and Pade test and exhibit what aquaponics can do, there are rows of lettuce, Swiss chard and flowers growing on beds with roots feeding off nutrient-rich water.
Nelson and Pade didn't invent the technology but have become worldwide leaders in the industry. What began as growing, teaching and consulting has also become a business of selling equipment and systems. Customers are hobbyists or families who want to grow their own fish and food, and commercial operations that want to grow for markets, stores or restaurants.
They have also been working with people from developing nations, which may have water or soil challenges to growing food with conventional agriculture.
"They all worry about food security and this is a system they can install," Pade said.
Nelson and Pade host workshops year-round in Montello — about 55 miles north of Madison — and have built and shipped systems to Europe, the Caribbean, Asia and throughout the U.S. They have published the Aquaponics Journal since 1997.
In January, the company moved from Nelson and Pade's home to a facility on the western edge of Montello. Systems are built there and Nelson, Pade and their staff are in the process of moving the greenhouse there, too.
Earlier this month, the company shipped what it calls a Living Food Bank to a Christian mission in Haiti. The mission wanted the system so people there can learn to provide themselves with food — the protein of the fish and the fresh vegetables — without having to rely on donations.
"One of our goals in our business and our life is to see that people are well-fed," Nelson said. "Protecting or patenting it would be more profitable, but it would not be compatible with what we believe in."
Nelson and Pade are putting into practice the research of James Rakocy, director of the University of the Virgin Islands Agricultural Experiment Station.
Rakocy, a Milwaukee native and a 1967 UW-Madison graduate, has been developing aquaponics for 30 years.
"They provide an important link," Rakocy said of Nelson and Pade. "They provide a valuable service in terms of getting good technology out there."
Rakocy, who serves as adviser to Nelson and Pade, has seen more interest in aquaponics in recent years.
"It's dovetailing with the local food movement," he said. "When people started looking at where their food was coming from, you saw a growth in organic and local foods. Aquaponics is a natural process that has gotten more publicity because it's a nice concept."
At Nelson and Pade's greenhouse, fish tanks filled with tilapia are the first step in the process. The young fish come from AmeriCulture, a hatchery in New Mexico. In Wisconsin, a fish import license is required for fish that are not native to the state.
From the fish tanks, the water goes to a clarifying tank where the solid waste settles at the bottom and the mineralized, nutrient-rich water moves on to the plant beds.
The water, with the nutrients removed by the plants, then returns to the fish tank.
"If you look at the science of it, it's the same thing that happens in every pond and lake on the planet," Nelson said. "We're just doing it indoors."
Nelson and Pade monitor temperature, pH, dissolved oxygen and other water quality parameters. The process requires periodic testing and meticulous record-keeping.
"In aquaponics, your success is all about preventing things from going wrong," Nelson said.
The plants are grown with what is called the raft method. Floating rafts sit on 14 to 16 inches of water and are moved down the line from seedling to fully grown and harvested at the other end. The whole cycle of a plant's life can be seen in one row.
For now, Nelson and Pade have been distributing the fish and vegetables among their staff. Volume and variety are down because they're in the process of moving the greenhouse.
They have sold vegetables at markets and will sell at their new location in the future. The fish will be sold whole and on ice because of the costs and licensing involved in getting it processed.
Nelson grew up in Oconomowoc and Pade was raised on a dairy farm south of Fond du Lac.
They moved to California in the 1980s, and produced instructional videos. They learned about hydroponics because they wanted to grow tomatoes at home in the winter. They didn't see a video on the market about hydroponics, so they made one that sold well.
Their interest in hydroponics grew, but as prices for fertilizer increased, they began setting up systems with fish tanks to experiment with aquaponics. They learned about Rakocy's research and found their life's work.
They returned to Wisconsin three years ago, and the company has been growing ever since, particularly in sales to hobbyists or families. They also sell to educators.
"It lends itself to home food production, which is a huge part of our business," Nelson said. "People grow their own herbs and lettuce."
Tilapia is a hearty and efficient fish for the system, Nelson said, but isn't the only fish that work. They have also raised bluegill, large-mouth bass, catfish, koi and goldfish.
Pade said there were as many sales in January as all of last year. They've kept busy with sales, manufacturing the systems, speaking around the world and building the new facility.
"We're very conservative about our growth," Nelson said. "We believe in the technology and we love what we do, and we want to be doing it for a long time."