Aquaponics at its most basic form is the union of aquaculture (fish farming) and hydroponics (growing without soil). Most aquaponics systems are very large (often hundreds of gallons of water) and are used for growing Tilapia and leafy greens. The systems I developed and tested used aquariums and grew microgreens from as few as five goldfish. With fluorescent lighting, half a pound of microgreens could be grown in less than three weeks.