Classic fry farming is also called a "Flow-through system." Normally, the fry is raised in well build tanks, fed with fresh stream water and receive commercial fish food in pellets.

Trout and other sport fish are often raised from eggs to fry. This method has been used for many years to stock streams with sport fish. Many cultured fishes such as catfish, tilapia, carp, many others) require no meat or fish products. This type of method is well-known for fish farming.