How to Build an Aquaponics System

With all the modern focus on health and fitness, everyone is looking for the most nutritious and vitamin-rich types of food. Well it turns out that all you need is to know how to build an Aquaponics system! With a bit of work upfront you’ll gain access to super fresh and incredibly delicious homegrown herbs, fruits and vegetables that’ll revolutionize the quality of your diet and if you want to, it can be an excellent source of income as well.

Although it might seem difficult at first, it’s actually quite easy to build an aquaponics system – you just need the right guide and that’s exactly what we’re here for today!

After years of experience, dozens of books and a mountain of information, I’ve done my best to compact it all into a quick and easy DIY guide on how to build an aquaponics system. There’s nothing that makes me happier than other people getting in on this superb type of gardening so without further ado, let’s begin!

As this is a fairly extensive article, be sure to use the index to guide yourself:

Index

• Introduction
• Choosing the Location
• General Design of a System
• Choosing the Type of System
• Setting Up the System
• Getting the 6 Main Components
• How to Build an Aquaponics System Step by Step

---

Introduction on How to Build an Aquaponics System

We’ll start with some basic notions and concepts before moving on to the main guide as these are essential if you want to successfully build a system.

What is An Aquaponics System?

Aquaponics is an ancient and sustainable food production method which combines the techniques of aquaculture (raising edible fish) and hydroponics (growing plants in water). The recirculating eco-system turns fish waste into fertilizer for the plants which in turn clean the water for the fish.

Why Combine Aquaculture and Hydroponics?

By blending the techniques used in aquaculture and hydroponics, aquaponics eliminates their major downsides.

Aquaculture requires daily removal of excessive nutrient-rich water from the system which must be replaced with fresh and clean water. This causes major financial and raw material losses. On the other hand, hydroponics requires very expensive nutrients for the plants and regular system flushing. Costs are high, and you also deal with waste disposal problems.

However, by creating a self-sustaining and tightly knit eco-system, aquaponics only requires fish nutrients as an input, turning the downsides of aquaculture and hydroponics into positives.

How Does It Work?

In short, aquaponic systems copy nature’s water flow and use it to grow plants in a sustainable and compact way. Fish nutrients are the only input necessary for an aquaponic system, making it a very cost-efficient way to grow crops.

Fish eat the feed and produce waste mostly in the form of ammonia secretions. Heterotrophic bacteria then turn any fecal matter, decaying plants and unconsumed feed into ammonia and different other compounds through a mineralization process. However, in increased quantities, ammonia is toxic to both fish and plants. Nitrifying bacteria turn ammonia into nitrite and then into nitrate which is consumed by plants.

Both types of bacteria develop in an aquaponic system as soon as nitrite and ammonia are available so you don’t need to worry about this step, it’s automatic.

Simply put, you have three live components in aquaponics; the plants, the fish and the bacteria which rely on each other to survive.

Bacteria clean the water for fish by consuming their waste. Then, through mineralization, the bacteria provide nutrients to the plants which in turn filter the water and it is finally returned as good as new back to the fish tank.

With minimum investment and maintenance, you can produce healthy and nutrient-rich food in the comfort of your own home or backyard.

Why DIY vs Pre-Built?

DIY has become very popular in aquaponics due to the low costs of building your own system and the gain of knowledge, satisfaction and unmatched ability to perfectly adapt it to your surroundings and needs. By having full control over your design, you can also be very conservative in terms of materials and supplies required which makes everything much more affordable.

In my opinion, the in-depth knowledge you achieve by planning, designing and building your own system is also invaluable. For any future modifications needed you won’t require the help of a specialist or expert as you’ll be able to simply take matters into your own hands. You can also take your skills to the market and create some custom aquaponics systems for your friends or clients!

Finally, the satisfaction guaranteed by successfully completing a project that provides an abundance of healthy and organic food for you, your friends and family, is second to none.

Choosing the Location of Your Self-Built Aquaponics System

One of the main advantages of DIY aquaponic systems is that they can be configured in any size and installed anywhere. You can either choose an indoor or outdoor setting for your project. However, if you’re considering an indoor location you should make sure that the plants get at least 4 hours of sunlight a day or alternatively you could purchase a hydroponic lighting installation.

So, what are the common indoor and outdoor locations? Popular indoor locations for aquaponic projects include the living room, kitchen or garage. However, you could choose outdoor locations such as the backyard, the porch, terrace, balcony or the side of your house.

You should also allow for scalability when choosing your location. This way, you can expand your project in the future without worrying about having enough space or making some unnecessary modifications to what you already have.

General Design of an Aquaponics System

Before going into details about the mechanical & live components and how to build an aquaponics system, you should know about its basic configuration. The concept is very simple and involves 3 main parts:

– A closed flow circuit which sources water from the fish tank delivers it to the plant tank where it’s filtered and then transported back to the fish tank;

– Additional mechanical components which aid in water transportation and distribution;

– Live components such as plants, fish and bacteria.

Simple enough right? But how do all of these pieces interconnect? Well, it depends on which type of system you decide to build. Let’s dive deeper below:

Choosing the Type of Your Aquaponics System

Aquaponic systems come in three configurations including Raft, NFT (Nutrient Film Technique) and Media Filled Bed.

• The Raft System (aka float, deep channel & deep flow) involves growing plants on polystyrene rafts which float on water in a tank separate from the fish tank. This system involves a closed circuit water flow from the fish tank into the raft tank and back. Beneficial bacteria develop throughout the entire system and help with water filtration.
• The Nutrient Film Technique (NFT) involves growing plants in narrow and long channels down which a thin film of water flows, feeding the plant roots with nutrients and oxygen. Water is sourced from fish tanks and cleaned through filtration units, it flows down the NFT channels and returns to the fish tank. However, because of the thin film of water, a separate filter is required as the conditions don’t allow beneficial bacteria to survive.
• The Media-Filled Bed method involves using a container or tank filled with perlite, gravel or other material to create the plant bed which is regularly flooded with water sourced from the fish tanks. The substrate breaks down waste and other solids and sometimes worms are added to aid in waste disposal. Although this method involves the fewest components, the production capacity is low.

All three are designed to include a hydroponic system and fish accommodation & filtration units. The variable components include filtration parts, plumbing systems, the types of beds and the frequency of air & water circulation.

How to Set Up an Aquaponics System

Now that you know everything you need to get started, it’s time to move on to the next step – setting up the aquaponics system.

Getting the 6 Main Components of An Aquaponics System

To start your aquaponics project, you need to know the system’s components. You can then create your own design and configuration (with enough creativity the sky’s the limit although you can always use pre-made designs that have already been tested) and decide on the best location for your project.

Aquaponic systems vary in size and style. You can choose between a small indoor system, a larger backyard project or even venture out and develop a commercial sized project (which is astonishingly profitable). Although aquaponic systems are easily scalable, they share the same components: rearing tanks, settling basins, biofilters, hydroponic subsystems (plant beds) and sumps.

Let’s take a look at these components.

1 – Rearing Tanks

A well-configured aquaponics system supports 1 lb of fish per 1 gallon of water. However, in the beginning, to test the balance, you should consider a ratio of 1 lb of fish per 10 gallons of water (a safe, foolproof ratio).

The fish tank is the heaviest and largest component of your aquaponics system, so you should first decide on its location. The size of your fish tank depends on your aquaponic goals. If you want to rear fish for food, the fish tank should accommodate at least 50 gallons of water for plate-sized fish. Also, it should be made from food-safe and non-toxic materials to guarantee high-quality and nutritious food.

An option could be tanks made from polyethylene and UV inhibitors. Tank covers are equally important because they prevent sunlight from triggering algae production in water and stop fish from jumping out of the tank. You can learn how to select the perfect fish tank for your system with this video:

2 – Settling Basins

Water sourced from the rearing tank goes through several checks before flowing into the hydroponics section of the aquaponic system. Any unconsumed food parts or other particles found in the water drop in the settling basin. This unit prevents them from entering the hydroponics part of the system. The cleared water then passes through the biofilter.

3 – Biofilter

The biofilter is a surface area populated by beneficial bacteria. They’re required to convert toxic ammonia waste and nitrites into dissolved solids and nitrates used to feed the plants.

Although these bacteria naturally develop in the water of the fish tank, your aquaponics system requires a higher density. That’s why bio-filters are installed, to provide additional space for bacteria to develop.

You can choose from a wide range of horizontal or vertical bio-filters. However, media-filled grow bed aquaponic systems combine the biofilter and grow beds into a single unit.

4 – Hydroponic Sub-Systems

The best hydroponic sub-systems for DIY aquaponic projects are provided by the raft and media-rich methods.

Sand or gravel sub-systems eliminate the need to have a separate bio-filter as nitrifying bacteria can develop in the substrate. Also, the substrate helps filter the water which flows through before returning to the fish tank.

However, supporters of the raft or floating technique argue that gravel or sand substrates are very heavy and can clog the system easily. This could lead to insufficient biofiltration, water channeling and a lower quantity of nutrients being delivered to the plants.

They both have their pros and cons, check out the video below to learn more about each media’s pros and cons:

As shown in this incredibly useful study, published by Wilson A. Lennard and Brian V. Leonard, the NFT hydroponics sub-systems have a lower capability of removing nitrate and other nutrients from fish tank water and have lower plant yields. This gives us some great insight into how it works in an aquaponics system and personally leaves me more inclined to use other types of media such as the classic “Gravel Bed” or the “Floating Raft” instead of the “Nutrient Film Technique” (NFT).

Another thing to consider is the type, shape and size of the aquaponics grow bed that’ll hold the media. Here’s a great video by a fellow aquaponics team that helps you choose an adequate grow bed for your system:

5 – Sump Tanks

The sump tank is the lowest point of an aquaponic system. It collects water drained from the grow beds which are not positioned high enough for the water to flow directly into the fish tank. A float switch is used to activate the pump which returns the water to the fish tank when the water level rises.

Sump tanks are used as gravity drain devices and to control water levels. Have a look at their understated usefulness here:

6 – The 3 Live Components

The live components of aquaponic systems include the plants, fish and beneficial bacteria (nitrifying and Heterotrophic). Sometimes, you can add worms in media-filled aquaponic systems which help by breaking down solids.

The plants and fish you choose for your aquaponic system should have similar needs in terms of temperature and pH levels. The closer you match these indicators, the more efficient your system will be.

In general, you’re better off with freshwater fish and leafy plants such as herbs or lettuce. However, if you’re aiming for a system with a high density of fish you could have some luck growing peppers, tomatoes or other fruiting plants.

1 – Plants

The most suitable plants to grow in an aquaponic system are herbs and leafy vegetables. Usually, they have low nutrient requirements and are easier to grow. You could choose anything from spinach, lettuce, watercress, coriander to parsley or lemongrass.

If you want to grow fruiting plants such as tomatoes, peppers or eggplants, you’ll need a decoupled setup so you can add more nutrients. However, you could also choose to grow smaller root plants such as leeks, radishes or onions which are suitable in a decoupled or recirculating system. Larger root crops such as carrots or potatoes grow better in soil environments, so you should steer clear of them.

To learn more, make sure to read the full list of the best plants for aquaponics.

2 – Fish

You should choose your fish depending on the climate of the region where you live. For example, Nile Tilapia do very well in warmer climates. You can install a water cooler in the hydroponics system to control temperatures during summer.

If you live in a cooler area, trout can be a perfect choice for you. You should focus on providing the best rearing conditions for your fish so they grow and stay healthy. Other fish raised in aquaponic systems include bluegill, sunfish, crappie, koi, goldfish, carp or catfish.

To discover which species are better suited for your system, read the best fish for aquaponics article.

3 – Bacteria

Bacteria is one of the most crucial live components of your aquaponic system. Both heterotrophic and nitrifying bacteria decrease water toxicity levels. While heterotrophic bacteria turn fecal matter and other solids into ammonia, the nitrifying bacteria process the ammonia and produce nitrites & other compounds. Through mineralization, the bacteria guarantee a safe living environment for fish and produce fertilizer necessary for the plants. They’re generally called Beneficial Bacteria and regulate the influx of damaging bacteria which cannot develop in an already bacteria populated area.

How to Build an Aquaponics System Step by Step

Building an aquaponics system step by step is a more straightforward process than you might think. Although I’ve already covered how to actually design and construct one (including all the parts) in a step by step manner in the DIY Aquaponics article, I’ll write the outline here. In short, building an aquaponics system is as simple as this:

1. Find a location
2. Choose one of the 3 types of system
3. Make or Get and fit all the components (rearing tank, settling basin, biofilter, sub system, sump tank, etc…)
4. Choose and install the fish
5. Choose and install the plants
6. Do a test run to check for any issues (such as leaks, among others)
7. You’re finished!

Keep in mind that you can adapt these steps to your own particular situation. The components for example can include adding an auto-feeder, a temperature controller, growing lights, and everything else that you want or need.

Now the true fun of it all is that even though these are the main steps, you can give the system your own personal flare in both design and materials. Some go for plastic while others go for metal or even wood, which I appreciate more as well, for example.

If you want a more detailed explanation for each step, be sure to read our DIY Aquaponics guide – it’ll guide you through every step of building your very own professional aquaponics system from start to finish!

---

Conclusion

Communities worldwide are transitioning towards aquaponics in response to the increasing amount of harmful and unhealthy substances used by the food industry as well as due to economic reasons. Aquaponics guarantees a sustainable and highly efficient way for you to produce healthy and nutritious food all year round, right at home.

Now that you know how to build an aquaponics system, you can easily develop your project and enjoy fresh food – including the fish – without having to worry about chemicals or other substances plus you’ll also save a ton of money and get to taste the unmatched deliciousness of homegrown produce!

As a side-note, if you want to get a professionally pre-built system that already comes completely ready to use, take a look at the aquaponics kit list to find the perfect one for you.

Thank you for reading and be sure to leave a comment or send me an email if you need any further guidance, I’ll be more than happy to help!