Aquaponics hardware: The 10 most important components of an aquaponics system at a glance

1. Fish Tanks & Sump Tanks | Fish Tanks

The fish basin, also called a fish tank , is the habitat of the fish. Every aquaponics system consists of at least one fish tank . In larger systems, several fish tanks are combined. For example , CHOP systems ( Constant Height One Pump ) work with fish tanks at different heights and use gravity for the water cycle. The lowest basin, where the water flows together, is also called a sump or sump tank .

Illustration of an aquaponics fish tank, round tank with overflow

Tilapia cichlids in aquaponics fish tank

2. Media Grow Beds & DWC Grow Beds | Planting Beds

The grow bed is the habitat of the plants. A rough distinction is made between media grow beds and DWC grow beds ( deep water culture ).

2.1 Media Grow Beds

Media Grow Beds are filled with Grow Media - a medium or substrate, usually made of planting clay or other clay granules. The Grow Media offers a lot of surface area for colonization by bacteria and microorganisms and therefore fulfils the tasks of biological water filtration very well. Here, bacteria and microorganisms convert the nitrite created by fish droppings into nitrate . This process supplies the plants with nutrients. In addition to biological filtration, the Grow Media also functions as a mechanical filter for solids such as fish droppings. These get stuck between the added Grow Media and can be broken down again in the Grow Bed, for example, using compost worms . The purified water then flows back into the fish or sump tank via the Grow Bed drain. The roots of the plants also find a hold in the Grow Media.

Most media grow beds are designed as an ebb and flow system , irrigated with a water inlet and equipped with a bell siphon for automatic drainage. There are also designs in which media grow beds are equipped with constant irrigation in combination with conventional drains. In this case, the grow media is kept moist by the circulating water from below. Such media grow beds are usually set up after a biofilter at a slightly lower height and filled with finer granules such as expanded clay or other clay granules. The function of biological and mechanical filtration is also maintained here.

Image of the Aquaponics Grow Bed BASIC from OFERA. You can find other variants in our hydroponics collection .

2.2 DWC Grow Beds & Floating RAFT System

If you want to cultivate your plants floating on a Floating RAFT in a DWC ( Deep Water Culture ) planting bed, the grow bed only contains water instead of grow media. In this case, the water must be cleaned using a separate, upstream mechanical and biological filter system . This type of cultivation is particularly common in commercial systems and also produces excellent results. In this case, the beds are usually around 40cm high and integrated into the water cycle of the aquaponics system. The plants are cultivated floating on so-called Floating RAFT boards with net pots or plugs . In this case, too, the nutrient-rich water fertilizes and moistens the plant roots from below. However, the water in a DWC grow bed should be continuously ventilated from below with an air pump so that sufficient oxygen can constantly reach the plant roots .

Illustration of a DWC (Deep Water Culture) grow bed in aquaponics

3. Bell Siphon | Bell siphon drainage at ebb and flow plant beds

Media grow beds are usually filled with grow media such as plant clay . There is still room in the hollow spaces for the roots of the plants and of course the water, which is evenly distributed throughout the grow bed. Once the desired water level has been reached, the water must flow back into the tank. This works best with a correctly dimensioned Bell Siphon. The standpipe of a Bell Siphon defines the height of the maximum water level within the grow bed - so that the roots of the plants are moistened. Once this water level is reached, the Bell Siphon automatically empties the grow bed. The grow bed can then be flooded again and the interplay between ebb and flow begins again.

Image of a Bell Siphon for 20cm grow bed height from OFERA. You can find other variants on the Aquaponics Bell Siphon | Auto Siphon Kit product page.

4. NFT modules | Planting tubes with nutrient film

Some plants, such as lettuce and herbs, are very suitable for NFT ( Nutrient Film Technique ). When cultivating hydroponics using NFT, the plants are placed in plant pots in pipes in which a film of water supplies the roots with nutrients.

5. Solid & Bio Filters | Filter Systems

If you do not use a grow bed filled with grow media, but a pure NFT and RAFT, the mechanical and biological filtration must be carried out by one or more filters. Especially for more ambitious aquaponics systems with higher fish stocking densities, it is advisable to also plan for additional solid and bio filters.

Solids filters use gravity and flow to filter out solids. Practical outlet taps on the bottom of the container mean that this “dirty water” can then be used as fertilizer for the garden. Biofilters contain a filter medium with a large surface area for bacterial colonization and are pumped through with air pumps and/or circulating water. This allows bacteria and microorganisms to work optimally and convert the nitrite produced by the fish excrement into nutrient-rich nitrate.

You can find out more about bacteria and microorganisms in this article ->

6. Plumbing Kits | Irrigation and drainage in aquaponics

The pump pumps the water from the fish tank into the plant beds via PVC-U pipes and hoses. It then automatically flows back again via drainage solutions such as the Bell Siphon.

7. Pumps | Pumps

The pump is the heart of an aquaponics system. When selecting it, you should pay particular attention to the performance. Maximum flow rate and discharge head are the most important indicators.

8. Air lift

9. Grow Media | Planting medium

The plants are usually cultivated in a pH-neutral, natural substrate, also known as grow media. The roots take hold in this and the bacteria and microorganisms settle on the surface of the medium, so that in addition to mechanical filtration, biological filtration and the necessary nitrogen cycle can also take place.

10. Lighting

Indoor projects usually require good lighting, as natural sunlight is only available to a limited extent or often not at all. Thanks to new LED technologies, there are now very good, energy-saving plant lighting options. These offer the optimal color spectrum for the growth and flowering phases of the plants.

What components does your system consist of? Do you have any further questions? Share your project or plan with us! You can find the comment field below.