Aquaponics, the art of using recirculating pumps to provide habitat for fish growth and nutrition for soil-less agriculture, is commonly becoming available to everyday people via the information exchange on the interwebs. It is potentially a viable gardening technique for apartment dwellers and others who don't have access to even a small plot of semi-arable land, but does require electricity.
After reviewing systems and advice for days on end, I have decided that aquaponics practicioners are completely missing the big picture...that Humanity needs start utilizing other plant sources more effectively, and that using electricity to run pumps to grow tomatoes IS STUPID. Besides, when have Tilapia ever produced an attractive pumpkin? The answer, of course, is never.
Cattails, on the other hand, are efficient bog plants that have been staples in Native Americans' diets for thousands of years. Managed effectively, Tilapia could probably make some huge cattails, taro, watercress, duckweed, azolla, water chestnuts...and probably dozens of other potentially delicious yet unexplored margin plants. Even without fish farming, more bog plants should be explored as efficient (space and resource) fodder and food sources.
The electricity and equipment cost of aquaponics is another factor that is best forgotten until afterward, largely because the majority of people that practice aquaponics seem to be aquarium lovers who want to take their fish raising large scale, or hydroponic plant farmers who want to take their nutrition dollars away from store-bought salts. The pumping power to mechanically aerate and filter the highly stocked tanks will never be cheaper than just buying fish meat, expecially when you factor in fish feed and time. And frequent chemical tests. And the possibility of fish disease ruining your whole crop.
Just think about it.
There are very few people working on doing this sort of thing sustainably. Perhaps the best and easiest solution would be custom-built ponds with floating plant beds on the surface, with only inexpensive bubblers for aeration and circulation. There is still the fish feed issue, but perhaps it could be lessened with Azolla, Duckweed, Black Soldier Fly Larvae, and Redworms. All of which would need support systems and engineering, but are currently being done well on the small scale. There is still the solids issue. Solids are not really a problem if you have a garden, which everyone who can probably should have anyhow.
A few (mostly) sustainable residential backyard aquaponics practitioners:
Garden Pool - eggs, tilapia, vegetables. Run on solar power.
Aquaponics HQ - fish, duckweed, rabbits, Black Soldier Fly.