Basics of Aquaponics: 5 Key Elements of an Aquaponics System

There are five key elements of an aquaponics system. Each of these is necessary to run a successful aquaponics system. We'll go over each of these elements in detail below.

The 5 Key Elements of an Aquaponics System:

1. Fish

Fish plays a vital role in the aquaponics system as they will be the source of natural fertilizer for the plants, so proper selection of fish to raise in your aquaponics system is critical. To ensure the success of your aquaponics system it is important to know what is the best fish for your system.

Key things to consider when selecting the fish for your system:

1. Purpose: Aside from providing food for your plants, what is the goal of raising your fish? The easiest way to start your aquaponics system is to grow a few fish for recreation like goldfish or food like tilapia. You can expand to a larger scale in the future after you have gained experience and skills. 

2. Temperature: Different fish have different water temperature requirements. It is important to choose a fish that is adaptable to your temperature and weather conditions. Some fish such as trout, like cold water while some fish such as tilapia, prefer warm water. 

3. What crops are to be grown?Fish should feed well at the same temperature at which the plants thrive. Make sure that both your fish and plants have the same temperature requirements. 

4. Maintenance Difficulty:If you don't want to put much effort into maintaining your system, you can choose a sturdy fish that can live in dirty water and immune to parasites and disease. Some fish are hardy and don't require much care, while others are sensitive and costly. Koi and tilapia are easy to raise for a beginner. 

 

Most common fish types found in aquaponics systems

Tilapia

Goldfish

Koi 

Trout

Catfish

Bass

Edible

yes

no

no

yes

yes

yes

Temperature (F)

60-95

35-89

35-89

35-68

35-89

39-89

Carnivorous or omnivorous

omnivorous

omnivorous

omnivorous

omnivorous

omnivorous

omnivorous

Mature Size

1.5lb

4”

20lb

0.8lb

1.25lb

1-3lb

Maturity

9-12months

3yrs

3yrs

12months

12-18months

15-18months

2. Plants

There are many plants that you can grow in an aquaponics system, and picking plants to grow in your aquaponics system can be a fun part. However, different plants have different needs and thrive under different conditions. Making the right choice in aquaponics plants is essential to the success of the system and the success of your harvest. The most common plant types found in aquaponics systems are: lettuce, tomatoes, peppers, basil, cucumbers

To choose the best plant for your aquaponics system, read our related article: What are the best plants for aquaponics?

Don't limit your imagination to just these plant types. You can grow almost any plant variety in an aquaponics system.

 3. Bacteria

An aquaponics system requires beneficial bacteria for the fish and plants to thrive. Bacteria plays an important part in the aquaponic cycle. The bacteria transform fish waste into nutrients for the plants; this process is known as nitrification. 

Nitrification is a process in which organic compounds are converted into nitrites and then into nitrates. Nitrosomas do this, first, they convert ammonia into nitrite. Then the Nitrobacter converts nitrites into nitrates. Once converted into nitrates, they can be absorbed by the plants. These bacteria can be present in the grow bed, grow media, fish tank, and biofilter. 

Pathogenic Bacteria

Fish rarely harbor human pathogens. But aquaponics is not immune to food-borne illness. Backyard gardens and small farms don't typically produce enough food to require regular testing.

Best practices to keep your system healthy are:

• Keep animals other than fish (dogs, cats, rodents, birds) away from your system.
• Learn how to keep your fish healthy and follow those measures.
• Wash food before eating.

4. Fish Tanks

The fish tank is where your fish live, so choose the right fish tank that will help your fish thrive and make your aquaponics system run smoothly. You can use recycled bathtubs, stock tanks, IBC tanks, and recycles barrels as a fish tank if you choose to do a do-it-yourself fish tank.

Proper selection of fish tanks is critical to system design. Some key considerations are:

• Tanks must be large enough for the species selected. Rectangular tanks are rarely appropriate, primarily because they allow solid wastes to collect and rot in corners. Round fish tanks are recommended.
• Tanks should ideally have a central drain in the tank's bottom or a configuration that allows solid waste to get out of the tank easily. Mechanical removal of wastes is at least tedious, and at worst, produces "poop slurry," which will be challenging to handle.
• Choose a fish tank that is sturdy, durable, waterproof, and heavy-duty to withstand water pressure.
• Fish tanks should be inert, non-toxic, and food safe. 

5. Grow Beds

In aquaponics, your grow bed is the foundation of your system. This is where your plants grow, so choosing the right grow bed is crucial to how your whole aquaponics system works. For the success of your aquaponics system, it must be balanced. It means there must be a perfect balance between the amount of fish waste produced by your fish to your biofilter's performance and the plants that absorb the nutrients from the water. 

The rule of thumb is, start with the grow bed and the fish tank ratio of 1:1. The total volume of your grow bed should be equal to the total volume of your fish tank to ensure balance and sufficient filtration. You can expand once you're ready for a larger system. 

Things to consider in choosing grow bed:

• The grow bed must be strong and thick enough to hold the weight of the grow media, plants and the force of constant draining and filling of water
• Choose a food-safe non-toxic material for your grow bed.
• Avoid using metals because metals can corrode quickly and can cause an imbalance to your system and lower your pH.
• Choose a grow that is deep enough for a variety of plants to grow. The standard grow bed deep is 12 inches deep.
• Use a waterproof, grow bed. 

Summary

Understanding each of the elements of aquaponics is key to running a thriving aquaponics system. From fish selection to grow bed selection, it is important to think about your objectives and constraints before building your system. To learn more about aquaponics read "100 Best Aquaponics Resources" and subscribe to our Newsletter to get an update on new articles.