Biofilter for aquaponics: The biological filter, or biofilter, is a key component in the filtration portion of a recirculating aquaculture system (RAS). The biofilter houses the nitrifying bacteria and is the primary site where biological nitrification occurs. Common dish scrubber pads can also make excellent biofilter material. Download fact sheet at link.
How to Make Fish Food to Feed Tilapia
Grow your own vege AND fish at the same time! You'll use LESS water, produce MORE vege two to three times faster (because fish poop makes for happy healthy veges) and have your own supply of healthy, "organic" fish all year round.