London is getting an "aquaponic" farm capable of growing 20,000kg of salad and 4,000kg of fish a year in an old warehouse.
Developed by company GrowUp Urban Farms, it will be set up in east London.
Aquaponics combines fish farming with hydroponics – growing plants in a nutrient-rich solution without soil.
The trick lies in giving dirty water from fish tanks to the plants, which eat the waste. The clean water then goes back to the fish (pictured).
By using vertical growing techniques, GrowUp maximises the yield per square metre, a necessity in cities where real estate is so expensive.
The company backs up its proposition by saying food wastage is cut by bringing production closer to where people live. It says that a third of all UK food is lost en route to the plate.
Kate Hofman, the CEO of GrowUp Urban Farms, told Factor that that the model is easy to copy across the UK, and that there is an increase in demand for sustainable food production.
"I think there are other cities, like Manchester, Bristol, where there is a growing urban population, people are more interested in where there food is coming from," she said.
"Interestingly what we found is that by taking over an existing building we were much more able to customise the growing environment than if we had built a new greenhouse."
The prototype GrowUp box was a shipping container containing a fishtank with a greenhouse on top with 40 vertical growing columns, which can house 400 plants at a time.
Images via GrowUp Urban Farms