Milk Carton Raft System
Unable to find any river rock or granite suitable for a media system, we decided on a raft system. Unfortunately, the only material available was about 6 cm thick and broke into small balls when rubbed. This could prove toxic for the fish. After considerable thought (outside the box), we ended up using milk cartons. This ingenious approach proved very inexpensive, functional, and readily available.
The crates were turned upside down, measured for water height, then cut accordingly. Holes for the baskets were drilled on top. One crate was cut right side up to accommodate media which served as a biofilter. This was our first media/raft/milk carton Aquaponic system!