System Components for Aquaponics

Let’s quickly cover the main components you will need to build your own aquaponics system. First you will need a fish tank. How large should this tank be? Well that depends on many variables. How much are you willing to spend? How much space do you have? How many fish would you like to keep? There are many other variables appropriate to your situation, go through these and make sure you get the tank most suited to you. Generally most people starting out opt for a 1000L (about 264gallons) fish tank. The larger the body of water you are dealing with the more stable the water is in that container. Therefore a basic rule of thumb has been developed by members of the aquaponics community that it’s best to start off with a 1000L tank. This is a guide only and if you want to start with something bigger or smaller that is up to you. The tank is usually some form of plastic or marine fibreglass. When buying the product ensure that the material is safe for fish. The easiest way to ensure that the item is safe is to only buy “food grade” materials.

Next up in building your aquaponics system are the grow beds. Grow beds are where you place your plants on top of some media to be fed nutrients from the fish tank. Generally grow beds are made from similar materials to the fish tank, as long as it is also food grade. The grow beds are often around 3ft by 4ft by 1ft high but also vary widely depending on what you want and what you have access to. Grow beds are filled with gravel or clay balls (or other suitable media like scoria). Keep this in mind when working out the water holding capacity of the system. The grow beds are an essential element in aquaponics, not only do they hold your plants but they also hold your bacteria colony that converts the ammonia to nitrates (plant food).

The sump tank is optional but definitely an important part of the system. The sump tank is simply a water reservoir. If you only have a fish tank and some grow beds that means you pump the water directly from the fish tank into the grow beds. The water level in the fish tank will fluctuate by how much water you have to pump out of it into the grow beds. A wildly fluctuating water level in the fish tank is not good for the fish. In this instance you want a sump tank. You pump the water into the fish tank and it overflows into the grow beds (as one example) which drain into the sump. The fish tank contains a special overflow pipe (discussed in our next article) to stop it from emptying out if the pump fails.

The water pump is an integral part of the system. You need to move water around the system and you need to do it quickly and effectively. A system with a 1000L fish tank needs to have that water moved through the system about once an hour (this is also a rule of thumb). At the same time most people pump into the grow beds for 15 minutes and then let it drain for 45 minutes. So you might want a pump that can pump much faster than 1000L/hr. Sizing your pump is dependant on your system so do some research before buying.

Pipes! To move the water around the system you will need pipes and other plumbing fittings. PVC is the most prevalent piping in aquaponics but other pipe types are also often seen like polyethylene pipes and HDPE (high density polyethylene) pipes. To put the system together you need pipes in standard sizes, elbows and t-sections as well as some ball valves to control flow through the system.

Putting all these together and you’re starting to build an aquaponics system!

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The Nitrogen Cycle

This is one of the few scientific parts of the aquaponics process and it is not too complicated for someone with no technical background to understand. Put very simply, the process is underpinned by some serious science but we only need to know a few things about the nitrogen cycle: 

1. It starts with ammonia
2. Bacteria break the ammonia down into nitrites and 
3. Other bacteria break those nitrites down into nitrates which are plant food. 

That covers the nitrogen cycle.

Although there is a lot to learn when starting on your aquaponics venture none of it will be overwhelming or too technical. Part of the joy of growing your own vegetables and fish is that you’re getting back to nature. Although aquaponics is a science based process the act of growing vegetables and fish are the same. You need to grow fish in clean water where they can thrive and they need a good nutrient rich feed, usually in the form of pellets. You need to plant vegetables in a substrate that can support them and they need water and food, mainly in the form of nitrates.

The nitrogen cycle is an integral part of the aquaponics process. The waste from the fish is transported to the grow beds (by pumping water into the grow bed) which contain gravel or clay balls. This waste is then slowly filtered through the grow bed media. During this process the fish waste, which consists mainly of ammonia, comes into contact with bacteria that has taken up residence in the grow bed media. This is where the magic happens.

Want to learn how to make your own aquaponics at home? Visit Easy DIY Aquaponics today!

So where do these magical bacteria come from? How do you find them? Well you don’t need to. One of the most exciting components of aquaponics is your free bacteria colony. If you provide a continuing source of ammonia and a substrate (like gravel or clay balls) in your system the bacteria will arrive without invitation. They will multiply rapidly and start working hard for you to provide life-giving nitrates to your plants growing above them in the gravel. Once your nitrogen cycle is fully operational and your bacteria colony has grown to the proper size your system is said to be “cycled”. We will discuss cycling your system in a later article.

Another exciting element of this journey is that the bacteria colony grows or shrinks according to the level of ammonia in the system. A small system will have a small bacteria colony and a big system will have a bigger bacteria colony. The size of the colony is self-regulating depending on how much ammonia is available to process. If you have a small system that you decide to expand, guess what? You got it right – the colony will expand.

Just another one of the exciting benefits of growing your own food using aquaponics – the free bacteria colony.

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Introduction to Aquaponics

There is a new plant-growing technique that is catching on quickly all over the world. It’s easier than gardening and less physically challenging too. There are no studies available on the current growth but if you were tracking websites and internet forums you would be impressed with the high-speed growth of this new farming technique internationally. It is called aquaponics. It is the combination of the best parts of aquaculture (the farming of fish) and hydroponics (the farming of plants in a non-soil medium). Let’s cover these in a little more detail so that we can improve our understanding.

Aquaculture is the farming of fish in large quantities usually this is done in large tanks but sometimes aquaculture farms are located in rivers or dams.

Want to learn how to make your own aquaponics at home? Visit Easy DIY Aquaponics today!

The biggest challenge of aquaculture is water quality. Most fish species are very sensitive to the quality of the water that they live in. Usually these fish species occur naturally in flowing rivers or large bodies of water like dams or lakes. There are natural filtration processes at work in these waterways that filter the water and keep it clean and free of poisons. One of the by-products of the life of a fish is fish waste (a.k.a. fish poo). Fish poo becomes toxic to fish as it contains ammonia which is very poisonous to fish. One aspect of breathing underwater is that a fish also gives off ammonia from its gills. Both of these processes release toxic ammonia into the water which can kill the fish. In large bodies of water this is not a problem as the ammonia is washed away and dissipates after a while or is converted into other compounds which are not toxic to the fish.

Maintaining water quality – the process of cleaning the water of ammonia and other toxic substances and also establishing a healthy pH for the fish is an important and high maintenance element of aquaculture. This is achieved by removing large amounts of water and replacing it with fresh water as well as the addition of certain chemicals to control pH and other water characteristics. This can be costly.

Hydroponics on the other hand, is a plant growing process which is based on controlling the environment in which the plants grow in order to maximise growth and yield. In hydroponics the plants are planted in special media like ceramic balls or other suitable media and the water is filled with plant nutrients and passed through the growing media to feed the plants. Many hydroponic installations are indoors under lighting. Once the water has been used up it is regarded as waste. New water and new nutrients have to be provided. The lighting is special grow lights which are expensive to buy and to run. Hydroponics can be expensive too.

Enter aquaponics (cue dramatic music). The set up costs for an aquaponics (AP) system can vary from “next-to-nothing” to “buckets-of-money”, depending on what you choose. There are many AP systems which were made from recycled materials and therefore cost very little. The running costs however are much lower than comparable aquaculture and hydroponics systems. This is how AP works: you get a large tank to grow fish, you get some plumbing supplies, you put in some grow beds (large plastic or marine fibreglass containers, usually about 3ft by 4 ft by 1 ft deep) and some grow media like gravel or clay balls. You pump the water from the fish tank to the grow beds. The grow beds are planted with seedlings or direct seeded. The gravel media develops a bacteria colony that converts the fish waste (filled with ammonia) into nitrates. Now this is quite miraculous for two reasons: 1. Nitrates are not toxic to fish and 2. Nitrates are plant food! That is correct; you will probably have noticed in the past that most good fertilisers are packed with nitrates. Once moved through the grow beds the water is drained back into the tank – re-using the water.

Suddenly you have a process which acts nearly like a small eco-system. The fish eat food you provide and grow to become food later, they release waste into the water. The fish waste is converted into plant food in the grow beds thereby feeding the plants and the grow beds also filter and clear the water for the fish. It is not a closed loop system but it is very efficient. And this is why aquaponics is growing so rapidly; the maintenance on the system is very low and you get a high yield in plants (tasty, healthy edible vegetables) and you grow fish for protein. The running costs are low and the vegetables you eat have not been sprayed by poisons so they are healthier. All-in-all there are many advantages and very few disadvantages. Welcome to aquaponics!

Want to learn how to make your own aquaponics at home? Visit Easy DIY Aquaponics today!

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