The text and illustrations of this article are from
Organic Gardening and Farming October, 1973
Philip Mahan demonstrates how a fish is transferred from the fry tank to the barrel.
A biological food chain in the back yard produces fresh fish for the table and compost for the garden.
By Philip and Joyce Mahan
After some study and experimentation, we have set up a productive food chain-- table scraps to earthworms to catfish--in our back yard. The project is satisfactory in many respects, utilizing waste materials to produce fresh fish for food and at the same time yielding ample compost for a small garden. The material cost is minimal. The whole operation can be set up for less that $15.00. The equipment occupies only about 12 square feet of space, and the entire assembly can be easily moved if necessary.
The materials can be very simple: Two 55-gallon steel drums, three panes of glass 24 inches square, and a medium-sized aquarium air pump. One of the drums will serve as a tank for the fish, oxygen being supplied by the air pump; and the second drum should be cut in half to provide two bins for the worms. The panes of glass are used as covers for the worm bins and fish tank, and for ease and safety in handling can be framed with scrap lumber.