Reuse for aqua-culture
The fertilization of aqua-culture ponds with wastewater and excreta has been practiced for thousand of years in Asia. Today it is largely utilized in countries like India and Peru for growing carp and tilapia and certain aquatic crops such as water spinach (Ipomoea aquatica), water chestnut (Eleocharis dulcis and E. tuberosa), water hyacinth (Eichhornia crassipes), etc.