Small Scale Backyard Fish Farming

Looking to start homestead fish farming? Small scale backyard fish farming doesn’t have to be difficult, unsustainable or expensive.

Using inexpensive and readily available materials such as an aboveground swimming pool you can get fresh fish from your back yard. “By raising your own fish, you can achieve a higher level of self-sufficiency and provide a healthier diet for your family,” says Steven Van Gorder, author of Small-Scale Aquaculture. “Backyard fish farming is as practical as gardening for producing food for the family.”

Van Gorders book explains backyard aquaculture in detail, with plans and step-by-step instructions that can help you successfully raise fish even if your only source of water is a garden hose.

Puanani Burgess, executive director of the Waianae Coast Community Alternative Development Corp. in Waianae, Hawaii, says the methods “look so simple that everyone thinks, ‘Hey, I can do it.'” Fourteen years ago, Burgess’ group formed a micro-aquaculture cooperative, which hundreds of islanders have participated in over the years.

“It is really ideal for small, rural communities like ours,” Burgess says.

Image by James Rakocy/Alternative Aquaculture Association

This aquaculture system in St. Croix, U.S. Virgin Island, yields several hundred pounds of red tilapia each year. These cages have demand feeders — the fish strike a rod that releases food pellets into the water.

Historically, aquaculture has something of a bad reputation because it has been limited to large commercial facilities that require significant amounts of water and energy, and thus can be major sources of pollution. In contrast, Van Gorders systems blend 4,000-year-old cultural practices with refined modern techniques — using minimal energy and water — and put you in control of the purity and healthfulness of this food source. (For healthy and sustainable choices when you do buy seafood, see The Health Benefits of Eating Fish. — MOTHER EARTH NEWS)

There are several similarities between gardening and fish farming: Both plants and fish need food and warmth; just as certain plants favor different seasons, there are cold-hardy fish and heat-loving fish; and both sorts of “gardens” require regular maintenance — you can’t just scatter a handful of seeds or sprinkle a few fingerlings in a pond, then expect to harvest anything edible in a few months.

Van Gorder advises beginning fish farmers to start small — no more than 100 fish the first few seasons. Once you master a few basics, “you will be able to raise several species of fish in tanks, indoors or out, throughout the year,” he says.

In the Waianae cooperative, for example, a few aboveground tanks can produce more than 300 pounds of golden tilapia every six months.

close up of fish swimming in an aquaponic tank

Image by Unsplash/Bakhrom Tursunov

Types of Aquaculture Systems

Here are the four aquaculture systems Van Gorder describes:

Cage Culture. This aquaculture method “provides the simplest means of growing fish if you have access to a pond,” Van Gorder says. He estimates a cage system could be built for about $100. “The only cost is for cage materials, fish and feed.”

Small, square fish cage sits in a small pond. The cage is made of bamboo…

Image by Adobestock/nutpacha

Cage culture is one of the most affordable backyard fish-farming methods.

In this system, a cage or pen made of plastic pipe and rigid netting is moored in any suitable body of water — a pond, lake, stream or millrace — and stocked with fingerlings that are fed until they reach a harvestable size.

“If you have a farm pond, building a floating cage will provide enough fish to feed your family year-round,” Van Gorder says. Channel catfish is the most common fish grown in cages; tilapia, trout, salmon and hybrid striped bass are other options.

Flow-through. This method diverts a continuous source of cold water, such as a stream, spring or river, into “raceways” that hold fish. Even a small volume of water can create a more productive system than a closed setup. “With just a few gallons of spring water, you can grow trout year-round,” Van Gorder says.

Like cage culture, flow-through systems are simple and relatively inexpensive, unless you don’t have access to a natural source of flowing water. It’s also important to note that flow-through systems are subject to regulations regarding the diversion and use of natural water sources. Be sure to talk with local fish and soil conservation authorities before making use of nearby streams.

Greenhouse Aquaponics. Within some form of greenhouse, this method uses a variety of plants — instead of filters to improve the water quality for fish. In addition to tilapia, trout, catfish or hybrid striped bass, you can grow different vegetables — including tomatoes, lettuce and cucumbers — as you would in conventional hydroponics. However, because fish are living in the water, the nutrient sources for greenhouse aquaponics must be totally organic; no herbicides, insecticides or fungicides can be used.

A farmer harvests green lettuce from a hydroponics setup in a greenhouse

Image by Adobestock/orapin

Greenhouse aquaponics combines hydroponics and fish farming.

Greenhouse aquaponics is the most complicated aquaculture method, requiring a high level of management and components such as a water pump and aerator. Backyard fish farmers often combine aquaponics with a home recirculating setup (discussed later in this article). Altogether, such a system could cost up to $1,000, but using recycled materials can bring that price down significantly.

a greenhouse with plant boxes floating on flowing water

Image by Flickr/Brian Barnes

Home Recirculating. This is the answer for would-be fish farmers whose only water source is a garden hose. The best way to create this miniature fish farm is to use an aboveground vinyl-lined swimming pool in a back yard, garage or basement. The cost of such pools varies based on size, ranging from $300 to more than $2,000. They are durable, with only the vinyl liner needing replacement every few years.

fish being farmed in a recirculating tank

Image by Flickr/Bytemarks

Recirculating works for those who only have a garden hose.

For the ideal home recirculating system, Van Gorder recommends a pool 12 feet in diameter and 3 feet high. This size will hold about 2,000 gallons of water when filled to within 8 inches of the top. Unfiltered, that amount of water can produce only 10 to 15 pounds of fish, even with added aeration. But by controlling temperature, removing ammonia and waste, and oxygenating the water, that same amount of water can produce more than 100 pounds of fish in one growing season. Species best-suited to this system include tilapia, catfish, bass, carp and trout.

Because the fish spend all their lives in the same water, maintaining its quality is essential. Water must be clean, kept at the correct temperature and contain enough oxygen. Smaller pools have less margin for error and require even more management. Components of the home recirculating system include:

Solar dome. This is an inexpensive plastic cover that looks like a giant shower cap. Most of the fish recommended for backyard fish farming are warm-water species, which grow best at water temperatures above 80 degrees. In temperate climates, aboveground pools will reach about 70 degrees for only the warmest 12 weeks. But a solar dome will increase the average water temperature to about 80 degrees for at least 20 weeks.

Drum clarifier. This provides a simple way to collect and remove almost all of the organic material that accumulates in the water. Using siphons and a water or air pump, water flows between the pool and two 55-gallon drums that are filled with plastic mesh (orchard netting), which traps the solids.

Biofilter. This simple water wheel removes toxic ammonia from the water. It can be made with PVC pipe, corrugated fiberglass roofing and a few other materials available from your local home improvement store.

Aerator. An air pump or aerator adds oxygen to the water, which is necessary to raise healthy fish.

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Emergency power. To keep aeration and pump devices running during blackouts, it’s a good idea to connect the system to a generator; or connect a simple 12-volt agitator to a car battery. Water quality won’t suffer if filtration and clarification are cut off for a few hours, but oxygen levels will rapidly fall if there are many fish in the pool.

Stocking Your Water Garden

Once you decide which system makes the most sense for your circumstances, the next big decision is which fish to raise.

“With an eye toward ‘sustainable aquaculture,’ whenever possible the small-scale fish farmer should utilize those species whose nutritional requirements are more easily met because they feed low on the food chain,” Van Gorder says. Feed pellets for catfish, for example, rely on soybean meal. More than 1 pound of fish can be raised from 1 pound of dry pellets. Carnivorous fish — trout, salmon and striped bass — occupy a higher place on the food chain. It takes 3 to 5 pounds of wild-caught fish to make enough fish meal for pellets that will produce 1 pound of cultured, carnivorous fish.

Here are descriptions of your best options among warm-water species — tilapia, catfish, carp and bass and — cool-water species trout, salmon and perch.

Image by Adobestock/Behzadillustration

Tilapia. Tastes great and is one of the easiest fish to raise. Tilapia tolerate a wide variety of water conditions, including low oxygen levels and high concentrations of ammonia, and are resistant to diseases and parasites. Tilapia grow quickly under proper conditions — water temperatures of 64 to 90 degrees, with 84 degrees being optimal. Water temperatures less than 50 degrees are fatal. Java, blue and nile tilapia are the best species for backyard fish farming.