Good points @janton It is in one way...... the tilapia are omnivores and will eat black soilder fly larvae and duckweed. There are other things they can eat as well such as spirulina algae that can grow anywhere in the world. If you had a loss of power, yes this system would be a bit difficult to keep going. That's why I'm creating the Surthrival Trailer to house a mini micro-grid along with a food system like this. Yes it would be more work to get to a point of completely closed loop, but it is possible to grow all your inputs locally to provide feed for the fish.