The arlita , also called ripiolita , expanded clay or leca (in Argentina), is a dryceramic very light. The arlita also used as a filter in water purification. It gardening used for hydroponic culture systems as an inert substrate, replacing earth substrate. Its particle size is 5-7 mm diameters. The arlita applied to gardening must only contain expanded clay, eliminating metal manufacturing process that could affect the balance of ph and electro conductivity of the plant. This type of arlita gardening, can be made with any color (usually red) to give a different look to that used in construction, being equally valid if no color.