True dat. I wish him lots of luck, but if he has never farmed fish or never done hydroponic growing, he is in for some extreme learning. This isn't a zero-input system, since you are constantly extracting product. The write up I saw was using Tilapia because they were tolerant of the low O2 environment in the hydroponic water. Keeping all the parameters balanced has to be tough. The extreme setup only makes sense if there is a severe space constraint. I would expect higher yields from separate hydroponic and fish ponds, but still recycling all the nutrients.
Then again, what do I know? If he gets it running and starts making money hand over fist give me a ring