This system offers a cost-effective alternative to the Venlo greenhouse. Polytunnel greenhouses are often tunnel-shaped and quite simple in design, but are nevertheless ideal for seasonal, unheated aquaponics.
Polytunnels are inexpensive, quick to erect, and offer significant advantages over outdoor cultivation. The polytunnels typically come with a five-year warranty. While their transparency decreases over time, this has only a minor impact on the light quality for the plants. The polytunnels are typically storm- and hail-proof, but are susceptible to weathering, so a lifespan of about five years is expected. Polytunnels can be secured with ground anchors without foundations and relocated as needed. While the greenhouse technology in polytunnels is rudimentary, it does include effective automatic side ventilation.
European catfish is cultivated in the aquaculture sector. Deep Water Culture (DWC), growbeds, and AutoPots are used as hydroponic cultivation methods. The table shows the yield of our 500 m² sample system.
When calculating the costs for polytunnels, we usually assume around €100 per m², which works out to approximately €50,000. Due to the self-contribution, it was slightly less in this case. Additional costs for aquaculture, hydroponics, and other equipment amount to approximately €60,000, which is higher than the cost of the polytunnel.
In this example, however, the proportion of DIY work is high. All hydroponic modules were constructed from commercially available materials, such as L-shaped bricks, steel profiles, pond liner, etc., which kept costs low. The aquaculture tanks were designed specifically for this facility and custom-made by a plastics manufacturer.
The economic viability of a facility of this size is difficult to demonstrate for commercial purposes. Therefore, such systems are particularly suitable for self-sufficiency or community projects where personal contribution and community benefit are paramount.
In our example, it is a greenhouse with double film and an air chamber that provides surprisingly good insulation.
In seasonal operations, production is switched to winter crops at the end of autumn. While the fish enter hibernation, crop production is switched to low-nutrient plants. These plant species, such as microgreens or winter lettuces, are well-adapted to the lower light and temperature levels in winter.
| Product | Floor Area | Cycles/year / Stocking density | Yield | Cultivation method |
|---|---|---|---|---|
| Hydroponics | ||||
| red oak leaf lettuce | 144 sqm | 7 | 24.192 pcs | DWC |
| Tomatoes | 36 qm | 1 | 432 kg | Growbed |
| Chili | 36 qm | 1 | 260 kg | AutoPot |
| Aquaculture | ||||
| European Catfish | 55 sqm | 45 kg |
ready to cook: 380kg |
Smoked fish: 110 kg |
Gelderner Straße 139
47661 Issum
info@aquaponik-manufaktur.de
Gelderner Straße 139
47661 Issum
info@aquaponik-manufaktur.de