Aquaponics is a sustainable method of growing food. It incorporates both hydroponics and aquaculture in one low-maintenance system. Based on the nitrogen cycle, plants consume fish waste while simultaneously filtering the fish tank water. Fun and surprisingly easy, aquaponics is a wonderful hobby for families who want to eat healthy and spend more time together.
How Aquaponics Works
A simple, low-maintenance fish tank is set up. As the fish waste decomposes, it produces ammonia and nitrites, which bacteria then breaks down into nitrates. A pump carries the nitrate-rich water from the fish tank through a grow-bed, where plants consume the nitrates as food. The nitrate-free, clean water then returns to the fish tank, and the self-sustaining, mutually beneficial cycle begins again.
Benefits of Aquaponics
- Aquaponics is a totally organic process. Fish remain safe and unharmed since no chemicals are used.
- The plants effectively filter the tank water, so it takes less time to care for the fish.
- Aquaponics requires only one-tenth of the water used in traditional gardening.
- Growing food with aquaponics is less time-consuming and labor-intensive than traditional soil-based gardening.
- Unlike regular vegetable garden beds, aquaponics grow-beds are typically waist-high. That means there’s no bending/ painful back strain while tending to plants.
- Food grows anywhere with aquaponics; from inside a home, in greenhouses, outside in the backyard, etc.
- Aquaponics systems can be any size to suit your family or community’s needs.
Aquaponics System Methods
Media Bed System
A media bed aquaponics system is the most popular with hobbyists. In a media bed system, the media in which the plants are grown sits on top of or beside the fish tank. The pump brings water from the fish tank. The nitrate-rich water passes across the media bed, where the plants extract the nutrients they need. The fully filtered water then returns to the fish tank.
Nutrient Film System
The nutrient film setup draws water from the fish tank via a narrow tube, typically made of PVC. The upper surface of the tube contains many tiny holes, where the plant roots hang, absorbing the nitrates and other nutrients from the water. This system is perfect for areas with limited floor space since pipes hang from ceilings or run across walls. Nutrient film systems are very adaptable, perfect for plants such as leafy greens that don’t require a lot of attention.
Deep Water Culture System
Large commercial setups generally use deep water culture systems. These systems use a floating foam raft so the plant roots dangle down into the water, directly drawing nutrients. The water, filtered first to remove any solid fish waste, flows from the fish tank.
Creating An Aquaponics System
Step1: Set Up The Fish Tank
Adhere to the basic principles of fishkeeping. Allow plenty of space for the chosen species of fish. Use a standard acrylic tank. Many aquaponics enthusiasts also prefer to use large, food-grade containers or barrels with opaque sides. Before adding fish, dechlorinate the water and cycle the tank for four to six weeks. This allows plenty of time for the bacteria to proliferate in order to process the ammonia and nitrites into the nitrates needed by plants. Install a pump to draw water from the fish tank into the grow bed and back again.
Step 2: Construct The Media Bed
Build the media bed above the fish tank or beside it. Use a large, heavy-duty plastic container. Place it on top of a sturdy stand that’s strong enough to hold the weight.
Fill the media bed with your preferred media. Most people use clay pebbles, which retain moisture and are pH neutral, so the water parameters are not affected.
Ideally, apply a ratio of 1:1 between the size of the media bed and the fish tank (so that the volume is the same).
Step 3: Add Fish
When your tank has fully cycled, you can add your fish. Popular species that work well include goldfish, koi carp, tilapia, pacu, tetras, guppies, and mollies. More unusual fish species include silver perch, carp, barramundi, and catfish. These species are hardy, easy to care for and produce plenty of waste needed for good nitrate levels for plants.
Step 4: Planting
It is recommended to begin with leafy plants (such as lettuce, watercress, kale) and herbs (basil, mint, etc.). With more experience and enough fish, it is possible to grow tomatoes, peppers, beans, cauliflower, etc. Use seedlings. Place roots carefully into the media; make sure that they reach the water (which contains the nutrients).
Step 5: Maintenance
Feed the fish a high-quality, nutritious diet two or three times a day. Offer only an amount that is consumed within a few minutes. Avoid feeding the fish live food, as that can introduce parasites and bacteria into the tank. Tend to the plants just like a regular vegetable garden – however without the back-breaking weeding and watering.
Test the water every week to make sure that the pH, ammonia, nitrite, and nitrate levels are acceptable. Ammonia and nitrite levels should be at zero. If the plants are doing their job correctly, the nitrate levels should be negligible. The pH should be close to neutral, between 6.8 and 7.0. Once the initial cycle is complete, prevent the pH level from falling below 7.0 by adding calcium hydroxide and potassium carbonate powder alternately to the fish tank when required.
Reap The Harvest
As this introduction to aquaponics demonstrates, anyone can enjoy sharing their freshly grown, eco-friendly, organic food with family and friends. It is relatively easy to set up and maintain a simple media bed system. With aquaponics, Moving Happiness Home™ is a healthy, obtainable accomplishment.
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Alison Page, Guest Contributor
Alison Page is the expert contributor at Tankarium. With over 35 years of experience, Alison has been an avid fishkeeper since she was 12 years old. She began with a simple 10-gallon aquarium setup and two goldfish named Mister and Missus (although she never actually knew which was which).