Gardeners' Dirt: Aquaponics a balance between fish, plants
By Suzanne LaBrecque - Victoria County Master GardenerEdited by Charla Borchers Leon
Jan. 30, 2014 at midnight
Updated Jan. 29, 2014 at 7:30 p.m.
Last month, a friend asked, "What do you know about aquaponics?"
And I had to admit that other than growing something in water, I didn't know anything. So I decided my first new word for 2014 would be "aquaponics." And lo, when I looked into it, a whole new world of food production emerged.
Allows fish and plants to live off each other
Aquaponics combines aquaculture - raising of fish and snails - with hydroponics - raising plants in water - into one efficient system that produces both fish and plants. Basically, this rather revolutionary system allows fish and plants to live off each other in a mutually beneficial or symbiotic way.
Plants are grown in medium other than soil
During the past several decades, both home and commercial gardeners have become interested in growing plants in a medium other than soil. This process could be labeled nutrient-solution culture, water culture, nutriculture or gravel culture.
The first known attempts in hydro culture was in late 17th century England, when a scientist named Woodward was curious about the role of solid soil and water in plant growth. In the 19th century, English scientists had developed a method for growing plants without soil.
In the 20th century, scientists developed a solution culture for plants that allows successful harvesting on a large scale for commercial distribution. The only difference in growing plants in soils or nutriculture is how the inorganic nutrients needed for growth are provided to the roots.
Fish waste converts to plant-friendly nutrients
So, how does aquaponics work? The two main components of an aquaponics system are the fish tank and the plants grow beds with a small pump moving the water between the two. Basically, the wastewater in the fish tank is sent to the plant bed, and the nitrifying bacteria in the grow bed convert the fish waste in the water to plant-friendly nutrients.
The plants extract the nutrients in the water that promote growth, and the water passes through their roots, cleaning the water and recycling it back to the fish.
Flood, drain system
While many aquaponics system designs are available, the most common method is a flood and drain system. In this system, water is pumped from the fish tank up to the plant grow beds. Water then fills the grow bed and is gravity-fed back to the fish tank.
The grow beds have sterilized lava rock, clay, worms and other microorganisms that form the basis for a completely natural, nontoxic environment. This system is a closed-loop system because it is intrinsically organic.
Because of recycling, this system uses about 2 percent of the water a conventionally irrigated farm requires for the same vegetable production.
In balance, non-toxic
Are you wondering how you know if your system is in balance and nontoxic? A local aquaponics gardener, Rex Byrns, said, "My fish are my organic certification committee." Fish are very sensitive to environmental toxins. If his fish are doing well, then so are his plants.
Byrns built his first backyard aquaponics system two years ago and is now testing some plants for Texas A&M University in his expanded system.
Fish and plants raised in system
Some common fish raised in an aquaponics system include koi, goldfish, hybrid perch, sleepy cod and barramundi.
Some plants that do well in this system include arugula; leafy green lettuces; various herbs like basil, dill, mint, rosemary and vegetables; and flowers such as carrots, kale, peppers, tomatoes, watercress, strawberries, petunias, geraniums and violets. These plants prefer a pH range between 5.5 and 7.0.
Benefits from aquaponics system
Many benefits can be realized through an aquaponics system including:
Incredible productivity that yields large amounts of produce and fresh fish, thus reducing your grocery bills.
All-natural fresh foods grown without chemicals, fertilizers or pesticides.
Space efficiency because of vertical planting that takes about half the space required for a typical home garden.
Lower maintenance because there is no weeding, and maintenance can be as little as 15 minutes per day.
System can be built at a height appropriate for the gardener; thus, no bending, kneeling or reaching.
Aquaponics system uses about 1/10 of the water used to grow plants in the ground.
Yes, aquaponics systems are changing how some people think about raising food. And once the system is working, it's been described as poetic.
Kimberly Byrns, Rex's wife, finds the sound of the continuously flowing water to be very soothing. Perhaps aquaponics is good for both body and soul as well as our environment and vocabularies.
The Gardeners' Dirt is written by members of the Victoria County Master Gardener Association, an educational outreach of Texas AgriLife Extension - Victoria County. Mail your questions in care of the Advocate, P.O. Box 1518, Victoria, TX 77901; or firstname.lastname@example.org, or comment on this column at www.VictoriaAdvocate.com.