Aquaponics farm has to close?

Today I read that the Stadtfarm in Landschaftspark Herzberge has to close for good due to income losses - missing sales to the catering industry, fewer customers, and rising energy costs.¹ That’s a real loss for the area, because the concept of aquaponics is really fascinating.² By utilizing natural cycles, the breeding of edible fish (African catfish³) is combined with the cultivation of vegetables. The liquid excretions of the catfish serve as valuable plant fertilizer: they pass through a biofilter, where bacteria convert the ammonium into nitrate. The water is then used to feed tomatoes, peppers, chilies, and herbs, before cycling back to the fish. It’s a closed-loop system that works without soil or additional irrigation.⁴

The catch, though, is that the fish tanks have to be heated to a constant 28 degrees Celsius.⁵ I think this is where most of the rising energy costs came from, and with the ongoing energy crisis,⁶ it’s become unsustainable.

I hope they find a new concept to continue their work. Sure, you can’t feed a whole city with aquaponics, but there’s so much potential for research and for developing new solutions in this niche. It would be a shame to lose such an innovative project.

I always liked visiting the Stadtfarm. It felt like a glimpse into a more sustainable future, right in the middle of the city. Even if it was just a small operation, it showed what’s possible when you rethink food production and try to close the loop. It’s sad to see such a project struggle, especially when it’s clear that we need more - not fewer - ideas like this.