Can you really build a fish farm for less than $250...well it's possible. take a look at this next video as Mike tries to explain how he has been able to put together an aquaponics system for less than $250.
Now this system is self cleaning.
Below are details of how the system was put together
300 Gallon Tank $75
Gallon Drum $12
GPH Pond Pump $65
Filter Medium(Pea Gravel)$42
Misc Connectors/pipe $15
More Info: en.wikipedia.org www.backyardaquaponics.com