In this project, a conceptually novel off-grid zero-discharged aquaponic (fish-plant production) system with two anaerobic digestion systems is investigated through computer simulations and experiments on bio-energy recovery and nutrients dynamics. The anaerobic subsystems allow for efficient recovery of nutrients from the fish sludge and plant waste to enhance plant production. Deliberate acidification of the anaerobic system for enhanced nutrient release and pH control in an aquaponics and effects of VFAs on plant growth is researched experimentally. The focus is, in particular, on high-tech and climate-smart desertfood (aquaponic) systems in Namibia and Israel. Life cycle assessment of these aquaponic systems for environmentally sustainability will be performed, as well.