Today i read that the Stadtfarm in the Landschaftspark Herzberge has to close for good due to income losses (missing sales to the catering industry, less customers and rising energy cost).1 That would be a real loss for the area because the concept of aquaponic is really neat2: by utilising natural cycles, the breeding of edible fish (African catfish3) is combined with the cultivation of vegetables. The liquid excretions of the African catfishs are valuable plant fertiliser. It passes through a biofilter, where bacteria convert the ammonium it contains into nitrate. The water is used to feed tomatoes, peppers, chillies and herbs. Then it goes back to the fish. It works without soil or additional irrigation.4 The catch though: The fish tanks have to be heated to a constant 28 degrees.5 I think this is were most of the rising energy costs came from and the energy crisis is still going on6.

I hope they find a new concept to continue their work. Sure you can’t feed a whole city with it, but you can do so much research and maybe develop new solutions in these niche.

  1. It is also honourable that they don’t want to change to a producer for the rich and still want to produce and sell healthy and affordable food for the masses. ↩︎

  2. Although the concept is not new. For example the “chinampas” work like that and are way older. Here is a good introduction to this: However the aquaponic farms seems to be way better then the huge fish farms: ↩︎

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  4. There is a good detailed explaination here: ↩︎

  5. There are more things to consider ( but it seems to me that this is the main problem. ↩︎

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