aquaponics anyone?

I have seen a few videos on youtube about hydroponic farmers pumping aquarium/pond water through there system. Some even stick big fish like bass or trout in a circulating hyper oxygenated tank to provide nitrogen for the plants and have earth worms in the plant beds which are composed of only fine gravel to keep the roots trimmed and decompose plants like cilantro after cutting to make ready for new seeds. It looks really cool and I was thinking of trying something small scale, like a window garden, like that one day if I ever et around to it.