Aquaponics – How to Turn Fish Waste Into Delicious and Nutritious Food
Aquaponics: a hydroponic system in which the waste water from aquatic life is utilized to feed the plants instead of premixed nutrient solutions. This in turn filters the water for the aquatic life. This creates a symbiotic relationship between the two. Most hydroponic systems can be aquaponic systems just by adding fish. They just have to be closed systems. See the article on Hydroponics. Watch the Aquaponics Video of this article.
Aquaponics arrived in the agriculture research world in the mid-1970’s. Little has changed in the basic function and idea behind it since. They are still self-sustaining growing systems. What has changed, is the number of people around the world who are choosing to take part.
There are many different types of systems that can be setup. It depends on growing needs, location, space. A little planning, some elbow grease, and a few fish is all you need for one of these sustainable systems.
Whether the system is a large scale facility or a small in-home set-up, the basic concept is similar. Use as little soil and water as possible. A system that will yield a renewable source of protein and fresh produce. All with minimal waste of water or need for soil.
This process works by utilizing the beneficial waste of aquatic wildlife. It is used to nourish the plants grown within the system. The plants work as a natural filter for the water, which is then returned to the fish tank.
The plants that are grown within the system need nitrogen to thrive. The fish’s waste water is a natural source of this element. This water feeds the plants. It gets pumped from the tank to the grow bed where it is used to feed the plants. The water then drains through the bed and returns to the fish tank in a filtered state.
For many individuals this type of auto-rejuvenating environment is essential. It is for those who do not want to have to rely on a constant supply of commercial food sources. This is especially important if you choose to set up your homestead in an urban area. Could also be important in an area such as the colds of Alaska.
This can be a life saving practice in some areas. Areas where abundant water supply is lacking and growing conditions are harsh. Those living in areas that don’t get constant rainfall or have limited space, benefit from this knowledge.
Almost any species of fresh water fish can be used in an aquaponics system. The species of fish which are used most are:
- 69% Tilapia
- 43% Ornamental Fish
- 25% Catfish
- 18% Other Aquatic Animals
- 16% Perch
- 15% Bluegill
- 10% Trout
- 7% Bass
I have used tilapia, koi, catfish, goldfish and bluegill with good success. My next fish will be trout. You have to be somewhat selective of your species though. Select a species that can thrive in the water you are going to place them. You can’t grow tropical fish in water that is going to get colder than about 60 degrees farenheit. Some states prohibit growing some species indoor also. You might want to check.
There is a wide range of plants that can be grown using this innovative method. Commercial growers participating in studies on this subject planted a variety of produce such as:
- 81% Basil
- 76% Salad Greens
- 73% Assorted Herbs
- 68% Tomatoes
- 68% Lettuce
- 56% Kale
- 55% Chard
- 51% Bok Choi Cucumbers
- 48% Peppers
- 45% Cucumbers
Research shows that the plant production of this type of sustainable system is successful. It is beneficial to those who are in need of an design that will provide both vegetation and protein. A good aquaponics design will provide you with a supply of fresh veggies and a good source of protein. You can count on these systems to provide a year round harvest.
Proper pre-planning is essential to the success of your indoor growing system. Not all systems will be optimal for all situations or locations. Before getting started, there are a few things should consider. The amount of space available for growing, the type of produce you want, and location you are in, are just a few.
If you don’t have a lot of space you might consider growing vertically. Vertical hydroponics systems are available commercially or you can create your own. There are many design ideas on the internet.
You might want to start simple and develop more complex designs over time. I started with one aquarium and a planter. I then got another aquarium and more planters. Then I went outdoors with a 275 gallon tote converted to aquaponics. This utilized the cut off top of the tote for a plant bed with fish below. Next was an inground pond and four half 55 gal drums for grow beds. I now have greenhouse dedicated to aquaponics. You don’t have to be complex to start.
Many people think that having a system in the house for growing produce has to be ugly. Wrong. As long as you have some imagination, you can have a system that not only adds nutrition, but beauty as well.
When considering an aquaponics system for your home, you need to consider your location. The amount of sunlight, average temperature, and growing season of your area are important.
People who live in the colder climates may choose to invest some time and money into a greenhouse. Having a greenhouse can extend your growing season by quite a bit. It allows you to plant earlier in the season. Also, you can grow later in the season. I am in a climate that allows me to grow year round. If you live in a warmer climate, a greenhouse might not make much sense at all.
The types of foods that can be planted is nearly unlimited. That is if there is adequate space and the right temperatures. Although, It is best to plant produce that is commonly found in your region.
Not everything can be grown in an aquaponics system though. Some of the crops, like corn, that take a lot of space may not work well. Root vegetables, such as carrots and potatoes are grown using a wicking system. (see the hydroponics page)
With planning, you can enjoy a bountiful variety of fresh produce right in your own home.
The materials needed to create a home aquaponics systems include such basics as:
- Tank for fish – This could be as simple as a 10 gallon aquarium. I like a 55 gallon barrel or a 225-275 gallon tote. Both are readily available are recycled from food industry sources. Your tank must be food grade.
- Growing bed and media for plants – You will need a container that is water resistant. You can buy these ready to go, or you can build your own. I build a box out of cedar and line it with pond liner.
- PVC or other piping for water circulation – Do not use copper! Copper will kill your fish. I know from experience.
- Underwater pump – It needs to big enough to completely recirculate the tank at least once per hour. If you have a 100 gallon tank and you run it for 15 min/hour, then you would need a 400 gph pump.
- Aerator System – The fish need to have plenty of oxygen in the water. An airpump and a few airstones should do the trick.
- Fish – A general rule is no more than 1 fish for every 10 gallons of water in the tank. It would depend on the size of your fish though. Some people say 1 inch of fish per gallon of water others say 1 pound of fish for every 10 gallons. Just remember, they will grow, so figure on how much fish you will have when it comes time to start harvesting.
- Plants – The general rule for this is one plant per fish. Again, depends on the size of the fish and the plant.
Construction and design should be relatively simple and straight-forward. A larger fish tank is best. 250 gallons at least if possible. Larger tanks are more forgiving to changes in temperature and pH. You should also invest in a water testing kit. You need to know what the ammonia, nitrate, nitrite, and pH levels are.
When to Add Fish
The easiest way to get your tank ready for fish is to add a few gallons from an established tank or pond. If you don’t have any friends with ponds or aquariums, or don’t know where a lake is, you can always add a small amount of ammonia (1 cup/250 gal). In any case, start cycling the system (pump running, water draining cycle). If you start with your tank filled with water right out of the facet, you will need to at least wait a week or two before adding fish.
I always start with just a few fish first. Gold fish are available for just a few cents each. Dump a dozen or so of them in and wait a few days. They will help condition the water. If they are thriving you can add more of whatever species you like.
When to Add Plants
Plants can be added at any time after you start cycling the system. You probably won’t have exceptional growth at first however. It will take a few weeks for the system to start working. Some people add a small amount (1:1000) of liquid seaweed to the system. It is not harmful to the fish and will feed the plants until the system is fully conditioned.