Aquaponics is a method of gardening that allows people to grow both fish and plants in the same system. The systems are self-sufficient and do not typically require synthetic fertilizers or chemical pesticides. The fish eat, live and excrete waste in the tank, forming nitrites that turn into nitrates due to ammonia in the water. This waste is what your plants feed on. The idea of raising fish and vegetables together is a growing trend that provides healthier ways for people to obtain their food.
What You’ll Need to Start an Aquaponics System
For home gardeners, some of the items you need to get started are easy to source, while additional, more expensive equipment is needed on the commercial side. For a small, backyard aquaponic set-up, you’ll need:
- Food-grade, plastic totes (100 gal. or so)
- PVC piping and connections
- A small, submersible pond or water fountain pump
- A rectangular piece of rigid foam board sealed on one side
- Approximately 24 4-in. net pots
- One pair of nylons
- Fish fry and fish food
- Two or more large plastic totes or cement mixing trays
- A 5-gal. bucket to use with the bio-filter
- Medium-sized soilless grow media such as clay pebbles
Building a small aquaponic system is easy for the most part. Start off by learning how each component is used. First you have the fish tank, where you will raise fish, then the bio-bucket, which traps the larger fish waste particles and is also a great place for crayfish to live and breed. The mixing tray holds the floating, rigid foam board that contains the pebble-filled net pots where your plants will live.
Add in a series of gravity-fed siphon tubes for the water to flow back into the fish tank after the plants have taken up all the nitrates, and you’ve got yourself an aquaponic system! As the water falls into the fish tank, it gets mixed with a fair amount of oxygen to sustain the fish, but an air stone may be required in hotter months.
Once you’ve decided on the size of your system and have gathered the necessary materials, putting everything together is straightforward. A quick online search turns up lots of hits regarding the construction of these simple systems. There may be rules and regulations imposed where you live, so make sure you do your homework to see if this type of gardening is allowed. Permits may be needed.
For example, Californians are required to pay a permit fee of $850 for any commercial aquaponic operation. Any purchases made from online vendors will more than likely require additional paperwork and permit applications, too.
Fish and Fish Food
After your permits are acquired and your system is constructed, it’s time to source your fish. The fish need to be a species that is adaptable, grows fast and produces well in the type of environment you are able to provide. Many online companies sell small fish fry just for this purpose, or, like others have done, you can catch your own fish like bluegill or other types of sunfish, as well as crayfish or prawns.
Choosing the right fish to grow and consume is not an easy task. Most fish need room to grow and move around, so you have to choose a species that is hardy, robust and does not succumb easily to parasites or diseases. Tilapia are the No. 1 choice for aquaponics, with bluegill and other types of sunfish coming in second.
Captive-bred fish are vulnerable to parasites and diseases, which are unhealthy to consume or have in your garden, so always having fresh, clean water at the right temperature, along with adequate airflow and movement, will keep your fish healthy.
Fish food is the largest part of an aquaponic system’s operational cost. Most supplies can be found online or through a local vendor that specializes in fish farming. Always remember that what you get out of the fish is the same as what you put in. If starting from small fry, you will have to begin by feeding them a fine powder, and then change to larger-sized pellets as they grow.
The best advice on the proper type of fish food to use is one made from aquatic plants and vegetables—not from protein from land-based animals like pigs, cows and chickens. Fish mainly eat bugs and other aquatic insects, and what they eat changes their taste and texture.
Getting Organic Certification
Organic certification will not be required if you are just cultivating fish and crops for your own personal use, but if you plan on selling for profit, making corporate donations, or even just providing for others in your area, you may need your organic certification. One great source for this information is the US Department of Agriculture’s Agriculture Marketing Services website.
This is where you can find downloadable forms to fill out and learn how to find a certified inspector who will inspect your cultivation and packaging systems to ensure they meet or exceed regulations. The fee is normally around $250 and can be refunded up to 75% through the USDA. Permits are good for one year and come with detailed instructions on recertification.
How to Get to Market with Your Aquaponic Produce
Once you receive your organic certification, the next step is getting to market. Begin by designing a label with the USDA Organic Seal, make up a price list for your produce and fish, and visit some local farmers’ markets to get the lay of the land. Get creative with your webpage and printed flyers, and find out who the buyers are for your local restaurants who might benefit from what you have to offer.
The Cost Breakdown
Tilapia will eat all day if you let them. Most farmers feed their tilapia 4-5 times a day. It takes around 100-120 days to get a decently sized fish farm going and will cost about $125 to feed 50 fish. Each fish will sell for close to $6, which means your 50 fish will bring in about $300. Offsetting everything with the sale of your fresh produce will help increase your bottom line.
The basic pricing chart below should give you a better idea of what you can expect to bring in at a farmers’ market. Prices are based on local vendor markets in the Southwest Riverside County of California:
- 1 lb. of onions - $2.50
- 1 lb. of chives - $1.50
- 1 lb. of strawberries - $5.50
- 1 lb. of tomatoes - $2.50
- Bunch of mixed lettuce - $2.50
- Bunch of celery - $1.75
- Bunch of herbs - $2.50
- Bunch of leafy greens - $2
- Bunch of kale - $2
- Three bell peppers - $2.50
- Handful of fresh or dried hot chilies - $2
Profits and Losses
As with most small businesses, you will have some lean times. However, with an aquaponic system, you can tailor your production to reflect your business. You can have multiple stages of fish tanks going at the same time, with fish in different growing stages, along with the different produce you wish to sell. Alternating between fast and slow growth is the hardest part of mastering an aquaponic system because you don’t want too much of one thing. Here is a sample list of what you might consider offering at any given time, along with the costs of producing each item.
COST TO PRODUCE
$2.50 per fish X 10 = $25
$0.25 per bunch X 10 = $2.50
$0.25 per pound X 6 = $1.50
$0.50 per bunch X 3 = $1.50
$0.25 per pound X 5 = $1.25
$0.25 per bunch X 5 = $1.25
Total cost to produce = $33
ITEMS FOR SALE
$60 for 10 fish (not prepared)
$25 for 10 bunches of mixed lettuce
$15 for 6 lb. of tomatoes
$10 for 3 mixed bell peppers
$12.50 for a 5-6 lb. of onions/chives
$12.50 for a few bunches of mixed herbs
Total cost of items for sale = $135
What Grows the Best in an Aquaponics System?
From germination to harvest, most leafy greens take about 45 days. In my experience, most organic foods taste better when harvested early. Some leafy greens like celery, parsley and cilantro may take longer due to the water temperature being too cold in the early spring. Tomatoes, peppers, chives, onions and strawberries are all on about a 45-55-day cycle, whereas items like zucchini, squash, potatoes, watermelons, peas, beans and chilies all take around 50 days or longer. If you plan properly, you can have an ongoing harvest ready not only for yourself, but for your organic food business as well. Listen to what some buyers may be looking for, and see if you can fill that niche.