Build your own aquaponics system - what you need

Well, a tank for the fish, a tank for the plants and a pump to pump the water. That sounds very simple, doesn't it? Basically, these are actually the most important components for a simple high and low tide aquaponics system. However, there are a few basics to consider. We would like to give you the following tips for your project.

Fish Tank – Find a suitable container for your fish

The fish tank is the central unit of your system and also the habitat of your fish. For example, you can use an existing aquarium or a larger plastic container that is stable enough to withstand the water pressure. IBC containers are often used for this. The advantage is that they are stable enough thanks to an external metal construction. IBCs are also relatively cheap and relatively easy to get hold of. The upper part of the IBC container is then often separated at a height of around 30-35cm and then used as a grow bed. If you value the appearance, you can cover the container with wood or other materials.

Alternatively, we also offer some fish tanks in our shop . Here you will find fish tanks made of natural wood in various heights and sizes.

What do you need to consider when choosing an aquaponics fish or sump tank?

• Only use clean containers that have not contained chemicals or toxic liquids.
• Make sure that it is food-safe plastic that is free of plasticizers and heavy metals. (Polyethylene, for example, is a good choice)
• The tank must always be placed lower than the height level of your grow bed.
• Make sure that the container is large enough in relation to the size and number of fish. A small aquarium with 100 liters is more suitable for smaller ornamental fish. An IBC with several hundred liters is also suitable for food fish.
• If you use a glass basin, make sure it is on a suitable base and not directly on the floor.
• The volume of the fish tank should not be more than twice the volume of the grow bed. If you use several containers as a grow bed, their total volume counts.

Grow Bed – Find a suitable container for your plants

The grow bed is the living space of your plants and at the same time the mechanical and biological filter. Here too, only food-safe plastic containers are suitable. In contrast to the fish tank, you can also use several small containers for the plants. This actually has an advantage. You can then use abell siphon to cycle the drainage asynchronously so that the fluctuation of the water level in the fish tank is not so great. If you have already decided on an IBC , then the upper part of the IBC, which is around 35cm high, is now your grow bed container.

We often use grow beds with less volume, but then more of it. In addition to the advantage described above, this has another advantage: because the grow beds are emptied more often and at shorter intervals, you achieve a much better oxygen enrichment in the fish tank. This naturally has a positive effect on the quality of the water. If you are interested in the OFERA Grow Bed series BASIC and PRO , then take a look here .

What do you need to consider when choosing an aquaponics grow bed?

• Here too, make sure that you use clean containers.
• Food-safe plastics are of course necessary here too. After all, your vegetables grow in them.
• The grow beds should be at least 20cm high. Plant beds that are 20cm, 25cm and about 30cm high are common.
• The planting bed must always be placed higher than the fish tank on a stable substructure.
• Have you checked whether your grow bed reaches at least 50% of your fish tank volume?

Pump – Find a suitable pump

Finding the right pump is often not that easy. Perhaps you have already come across terms such as discharge head (water column), flow rate and power in watts in data sheets? What does that mean and which is the right pump for your system?

The delivery head describes the maximum height (water column) to which the pump can deliver water. The difference between the height levels of the fish tank (water level) and the upper edge of the grow bed (inlet) must always be taken into account. The delivery rate describes the maximum number of liters of water the pump can deliver.

Let's take a pump like this as an example. The device has a maximum discharge head of 2m and a maximum flow rate of 2000l/h. However, the maximum flow rate of 2000l/h is only achieved if the maximum discharge head is 0m. As the discharge head increases, the flow rate of the pump decreases again. This means the opposite: at a discharge head of 2m, no more water comes out.

For our first small project, we generally don't need more than 1m of head, as we are placing the grow bed directly above the fish tank. With a head of 1m, this pump can therefore manage around 1000l/h. Enough to circulate the water in the fish tank at least once an hour.

What do you need to consider when choosing a pump for your aquaponics system?

• The pump should be able to circulate the volume of water in the fish tank at least once per hour, taking into account the discharge head and flow rate.
• The pump should be completely submersible. (IPX8)
• If you decide to use a solar pump, you need to know that the maximum pumping capacity is only achieved when there is enough light or sunlight. In this case, it is a good idea to opt for a more powerful pump.

Flood and ebb system and the Bell Siphon drainage

To turn your grow bed into a flood and ebb system, you need aBell Siphon . The Bell Siphon directs the water that comes into the grow bed through the pump back into the fish tank. But this only happens once the desired water level has been reached. The roots of the plants need the moisture and nutrients from the water. Bacteria and microorganisms also take care of breaking down ammonium and converting it into nutrients for the plants. In this process, the water is also freed of toxins. You can find out more about this topic in this blog post .

PVC-U pipes, hoses and fittings

PVC-U is food-safe and even suitable for drinking water. In addition to the wide range of fittings and sizes, this is one of the main reasons why PVC-U is well suited for the pipes in aquaponics systems. PVC-U pipes, hoses and fittings (U, T and L pieces) are usually glued together with a special adhesive . Of course, you can also "just" plug them in and seal the plug connection with a Teflon tape . However, we only recommend doing this at the beginning or during the installation phase. Once the position of the pipes has been fixed, they should definitely be glued afterwards to prevent them from breaking open.

What do you have to consider when selecting PVC-U pipes?

• Always use a sensible pipe diameter between 20mm-32mm for the inlet to the grow beds. Larger pipe diameters are in most cases oversized and pointless for inlets to high and low tide grow beds. Pipes with a diameter of 25mm have proven to be the best.
• Flexible areas such as the pump connection should be connected using a flexible hose . This will allow you to remove the pump from the pool relatively easily if you need to clean or replace it.
• Use ball valves to regulate the water flow to the grow bed or other tanks. This allows you to throttle the pump and make the necessary fine adjustments for theBell Siphon.  simply carry out.

Do you have further questions about the basic components of an aquaponics system? Would you like to share your experiences with your project with us? You can find the comment box below.