What's one possible solution to urban plight? Fish poo. So say the eco-activists responsible for the GrowHaus, an indoor aquaponic garden located in one of Denver's toughest zip codes. Inside this former flower warehouse, a sprawling biology experiment is under way: When completed, rows upon rows of stackable bins, tubes and tanks will circulate the waste of live, growing fish for use as plant food. Nutrients in the plants, in turn, feed the fish. The result? Fresh fish and organic vegetables, both of which are in short supply in the Swansea/Elyria neighborhood. A community project led by real-estate developer Paul Tamburello and activist Ashara Ekundayo, the GrowHaus builds on the growing food-justice movement, which holds that a lack of access to healthy food contributes to a cycle of poverty in low-income neighborhoods. To change the 'hood, you've got to green the 'hood, they say, and that starts with what — and how — folks eat.