Setting up an Ecoponic System

The setup of an ecoponic system largely determines how stable, low-maintenance, and cost-efficient it will operate later. While the basic principles remain the same – a fish tank, a biological filter, plant modules, and a closed water cycle – the construction methods differ significantly in effort, material requirements, and costs. The following sections introduce the most common variants in a practical way, helping you make a well-informed decision for your own entry into the field. 

Building an ecoponic system is not just a technical project, but rather an attempt to recreate a functioning small ecosystem. The key lies in allowing organic diversity while gently supporting it with technology.

What works on a small scale can later be expanded: additional modules, more plant species, renewable energy sources. But every large cycle begins with a small tank, a few plants – and the willingness to let the system grow.

1. Basic System Elements

Regardless of construction style, ecoponic systems consist of the same core components:

• Fish tank: provides nutrients through excretions, size depends on desired stocking density.
• Mechanical-biological filter: converts organic waste into plant-available nutrients.
• Plant modules: absorb nutrients, clean the water, and form the visible cultivation area.
• Pump and pipes: keep the water cycle moving.
• Aeration: supplies oxygen to the water and root zone.

For beginners, it is advisable to combine these elements as simply as possible and to rely on robust components.

2. Construction Variants Compared

a) Media Bed Systems

In the media bed, plants grow in beds filled with substrate. Expanded clay, lava granules, or gravel not only provide support for the roots but also offer large surfaces for microorganisms. The water is flooded and then drained again (flood-and-drain).

Practice: Ideal for small systems starting from 300 liters of water and 1–2 m² of bed area.

• Advantages: simple construction, good filtration performance, high stability.
• Disadvantages: beds are heavy and space-intensive, cleaning is laborious.
• Costs: approx. €400–800 for a small starter system (fish tank, pump, two 1-m² beds, filter).
• Workload: 1–2 hours per week (control, maintenance, cleaning).

b) Deep Water Culture (DWC)

In DWC systems, plants float on water channels or tanks in styrofoam rafts. The roots hang directly into the water, which must be permanently aerated. DWC is widely used in aquaponics, also for large-scale production.

Practice: Typical are tanks 20–30 cm deep with floating trays.

• Advantages: easy to handle, plants are easy to insert and harvest.
• Disadvantages: oxygen supply is critical, risk of root diseases in case of imbalance.
• Costs: approx. €600–1200 for a small system (300-l fish tank, 2–3 DWC modules of 1 m² each).
• Workload: 1–2 hours per week, plus monitoring of aeration.

c) Nutrient Film Technique (NFT)

In the NFT technique, a thin film of water flows through channels or pipes where plants sit in net pots. The roots are continuously supplied with water and oxygen. NFT is particularly suitable for fast-growing plants such as lettuce or herbs.

Practice: Typical are PVC pipes (Ø 100 mm) or rectangular channels, 2–4 m long.

• Advantages: space-saving, small water volume in circulation, easy access to plants.
• Disadvantages: sensitive to interruptions (pump failure), risk of clogging due to organic material.
• Costs: approx. €500–1000 for 4–6 channels, fish tank, and filter.
• Workload: 1–2 hours per week, higher susceptibility to failures.

d) Vertical Systems

Vertical systems use the space upwards: plants grow in columns or wall modules, water trickles from top to bottom. This construction method is particularly interesting for urban spaces as it requires little floor area.

Practice: Use of PVC pipes or plastic columns with planting holes.

• Advantages: high space efficiency, attractive for demonstration setups and urban farming.
• Disadvantages: technically more complex, uneven supply to individual plants possible.
• Costs: starting at approx. €800 for a small system (6–8 columns with fish tank and pump).
• Workload: 2–3 hours per week, requires increased monitoring.

3. Selection and Recommendation

For beginners, the media bed system offers the greatest stability and the lowest technical hurdles. Those working with limited space may opt for NFT, but must expect higher monitoring effort. DWC is suitable for large-scale cultivation and research projects, while vertical systems are particularly attractive for urban farming, where every square meter counts.