You could do something similar with aquaponics as well. Plants eat the fish excrement, and the fish eat something that lives on waste like roaches or crickets.

You could do something similar with aquaponics as well. Plants eat the fish excrement, and the fish eat something that lives on waste like roaches or crickets. Maybe even some kind of shrimp, if you can get enough sunlight for a lot of algae. It does require electricity, although you could maybe get around that by having rain catchers up high to create a natural gradient and supplementing that by manually pumping water up into the reservoirs.