Are you interested in growing your own vegetables but don’t want to dig and plant a garden? Do you also love fresh fish but don’t live near a fishing spot? Aquaponics might just be the answer for you. Let’s look at some aquaponics designs for beginners to help get you started.
What is aquaponics? Aquaponics is a system of growing food similar to hydroponics (growing plants in water instead of soil). Aquaponics goes one step further, in that it involves the use of live fish to provide nutrients to the plants. The plants in turn help clean the water for the fish to live in. With aquaponics, you can grow not only your veggies for dinner, but also the fish to eat along with it.
Planning your aquaponics setup can be a daunting task. Some of our early aquaponics experiments involved growing plants in goldfish and betta aquariums (you can read about those in this article). Of course those were very tiny experiments. If you’d like to grow more abundant veggies and fish big enough to eat, you’ll need to think bigger.
Some questions to ask yourself before you begin:
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What do you want to grow? Some types of crops do better in aquaponics systems than others do. Lettuce is magnificent in aquaponics, but there’s just so much salad a person can eat. blah blah blah You will need to take note of the temperature range, growth rate and nutrient demands of the crops that interest you. You will need to tailor your system to the needs of those plants – or change the plants to fit your system.
What is your environment like? Do you live in a year-round warm area, or do you have a proper cold winter? How will you heat your aquaponics room? Or cool it? If your system will be outdoors, how will you shield your fish and crops from the temperature and weather extremes of your area?
How big is your gardening space? Do you have room to spread out and build a large system, or is your space limited and must be maximized to its fullest potential?
How much do you know about gardening and fishkeeping? If you are a beginning gardener or have never kept fish, learn everything you can while starting small. You can always build a bigger system later, but nothing is more disheartening than going all out and having fish or plants die on you. Who will be caring for the system most of the time? Will it be you, or someone else? If you have back problems, can you bend down to harvest from an in-ground system or do you need something built taller?
There are three main types of aquaponics designs.
1. NUTRIENT FILM TECHNIQUE
Nutrient Film Technique, or NFT, systems are common because they are so easy to build and use. A closed tunnel, or channel, holds water which circulates dissolved nutrients past the bare roots of the plants. The amount of water is very shallow, no more than a thin film (hence the name), which allows the roots to form a thick root mat. This type of system is best used for leafy greens, as other types of plants might be too heavy for the channels, or the channels might get clogged by plants that grow a lot of roots. In hydroponics (soilless gardening without fish), nutrients would be added directly to the circulating water. With hydroponics, the fish supply the nutrients through their waste. The bigger the growing system, the bigger the fish tank should be.
What’s good about NFT? NFT systems can be built vertically, so if you have a small amount of space, you can use it very efficiently. The vertical possibility of these systems mean the crops are easily accessed for harvest. Water is continuously circulated and can be put on a timer to run for a few minutes every hour, reducing the amount of maintenance the system needs.
What’s not so good about NFT? These systems are prone to temperature fluctuations, particularly in large setups. The plants’ roots can clog the closed channels, and these systems are not advised for large or flowering plants.
2. MEDIA BED SYSTEMS
Media bed systems use containers filled with a rock media such as gravel or expanded clay pebbles. The bed is flooded and drained by a pump on a timer. These systems are not as easy to build on a large scale, and are better suited for tabletops and back yard or patio gardening. The media supports the plants in much the same way that soil would, and because of that support, media bed systems are capable of growing plants with large root masses. The photo here is of a media bed system on a desktop aquarium. This system can be purchased as a kit on Amazon by clicking the image.
The image on the right shows the aquaponics system of Patrick Henry High School in San Diego, California.
What’s good about media bed systems? Media bed systems are easy to set up, relatively inexpensive, and don’t require a lot of technical know-how to get started. Systems can be small enough to grow plants in desktop aquariums (read about my desktop hydroponics experiments here) or scaled up to patio-sized systems like this high school built. The media acts as a filtration system to help keep the water clean for both plants and fish. Larger crops and flowering plants are possible.
What’s not so good about media bed systems? The media can get yucky and there is some maintenance involved in keeping everything clean. It’s harder to build a large-scale media bed system and is not recommended for anything other than household gardening.
3. Deep Water Culture
Deep Water Culture systems (DWC) are also called raft or float systems because, as those names imply, the plants grow in net pots on floating rafts. The plants’ roots hanging down into a deeper pool of water, usually around a foot deep, but can be deeper if the fish you choose will grow big enough to need it. DWC systems can be expensive to set up, and filtration needs to be carefully planned.
The picture on the left shows a large DWC system, and the picture on the right shows a closer look at the styrofoam raft.
What’s good about DWC? Deep water means more room for fish to grow, if you are going to have part of your tank exposed to the air and grow the fish under the rafts. However, this means fewer plants can be grown in it, so the fish are better kept in a separate tank with the water moving from tank to tank. The rafts and net pots are inexpensive, and the greater amount of water means the water temperature will fluctuate less. If you are planning a commercial aquaponics system, this is probably the type you should consider.
What’s not so good about DWC? DWC systems require a higher level of knowledge to build and maintain. The filtration system for the greater amount of water necessarily needs to be larger, and the size of the tank can be prohibitive for many people.
4. Hybrid Systems
Hybrid systems are basically what they sound like – systems where the owner picks and chooses elements of the other three systems and creates a custom setup. If you are a DIY person, it’s going to be easy for you to pick and choose the elements you’d like to incorporate.
What are the necessary parts of an aquaponics system?
All systems need certain parts. These are:
- fish tank – where the fish will live and grow
- grow bed and bed support – this can be the pipes in an NFT system, the floating rafts of a DWC system, net pots, or other containers such as food-safe plastics. I’ve used the black plastic nursery pots for plants, but without dirt, to hold expanded clay pebbles in an experimental indoor system. You will also need some sort of support for the pipes in an NFT system.
- Pipes and fittings – of course you’ll need some way for the water to get from your fish to your plants and back again.
- Water pump – be sure it is sized accordingly for your system.
- Water aerator – to keep the fish water oxygenated.
- Timers and controllers – these are used to cycle the water pump on and off, turn the grow lights on and off, and to regulate the heat of the water.
Other parts of the systems are optional, or the need depends on the type of system you build. These parts include:
- Sump tank – depending on the design of your aquaponics system.
- Bell siphon – for “flood and drain” systems like NFT.
- Grow lights – if your system doesn’t get enough natural sunlight.
- Heater – to keep the fish water at optimal grow temperature or to heat the water enough to encourage plant growth.
- Grow media – for media bed systems. This can be expanded clay pebbles, small gravel, or rockwool.
- Monitoring equipment or software – depending on your circumstances and if you’d like to spend the extra money on it, you can buy software that will help you run your system.
What types of fish can be grown in an aquaponics system?
The type of fish you can grow in your aquaponics system depends on the climate in your area, legality of owning the fish, and the size of your system. Check with your local fish farming laws to make sure you’re following the rules, but chances are, the fish you want to grow in your system will likely be fine. Pay attention to the size of your system and the size your fish will grow to be… you don’t want to overwhelm your filtration system with fish waste, or crowd the fish. Some fish do better in warm climates and some do better in cool climates, so do your research before you buy.
If you choose an ornamental aquaponics system (like a desktop aquarium), then you’ll have to stick to small ornamental fish – tetras, gouramis, goldfish and bettas. Large ornamental systems are popular, too, and brightly-colored fish like koi are great for those.
Larger systems intended to grow fish for the dinner table have other options. Probably the most common aquaponics fish is the versatile and delicious tilapia. Tilapia have a fast growth rate and are ready to harvest between six and nine months of age. They reproduce quickly too. Because tilapia are top feeders, it’s easy to check their growth when they come to the surface to eat their meals. Tilapia do like warmish water, though, so if you want to raise them in a cool place, allow for a heater in your plans.
Trout is another good choice. A tasty member of the salmon family, trout do well in cooler climates and can eat a varied diet. Because they are carnivorous, they can’t be kept with any other types of fish.
Catfish are bottom feeders that can be kept with other fish within your aquaponics system (tilapia in particular). Be aware, though, that catfish require a high-protein diet, and are easily stressed. They need more room than other fish, too, so they are best for big systems.
Other good choices for your aquaponics fish are perch, largemouth bass, and sunfish.
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