The film was mostly funded out of the filmmakers' own pockets. Director Shane Abbess worked as a building laborer, a removalist, at a call center and as a dockyard truck driver simply to raise money for his film. Five weeks into shooting when it looked like the money was about to run out, he was prepared to return to his job as a removalist when his old boss gave him sufficient funds to complete the film.
For the rain effects, instead of using expensive rain towers, the film's climactic scenes were done simply by using hoses. However, because the water was unheated, production had to be stopped three hours early because lead actor Andy Whitfield became hypothermic, his temperature dropping to 32.5 degrees Celsius.
The art department saved money by obtaining all their props and costumes from local thrift stores. In addition, they saved money on dressing sets by using abandoned industrial locations and condemned buildings.
Shane Abbess studied other low budget films like Requiem for a Dream (2000) and Donnie Darko (2001) to see how other filmmakers worked on such small budgets.
Just before production began, the company who was set to insure the film dropped out and the production team were forced to go with someone twice as expensive. This shrunk their tiny budget considerably, with the result being that the film was almost shelved.