NOVELTY - The solar still module (10) for producing fresh water from saline or brackish water, comprises a treatment chamber, a water treatment member positioned below an upper extremity of the treatment chamber, a unit to supply water to be treated to be spread over a treatment surface zone in a thin gravitational surface flow, a space frame (12) with an outer flexible skin (43) formed by a plastic material film web (44), a condenser unit, a fan unit to move gas and/or vapor flow over a black or darkly opaque panel, and a heating unit.    USE - The solar still module is useful for producing fresh water from saline or brackish water.    ADVANTAGE - The solar still module ensures an effective operation thus providing enough clean fresh water in an economical manner for many purposes including drinking water and irrigating crops without salt build up in land structures commonly associated with use of artesian water.    DETAILED DESCRIPTION - The solar still module (10) for producing fresh water from saline or brackish water, comprises a treatment chamber, a water treatment member positioned below an upper extremity of the treatment chamber, a unit to supply water to be treated to be spread over a treatment surface zone in a thin gravitational surface flow, a space frame (12) with an outer flexible skin (43) formed by a plastic material film web (44), a condenser unit, a fan unit to move gas and/or vapor flow over a black or darkly opaque panel, and a heating unit. The water treatment member defines an upwardly facing surface treatment zone. The treatment chamber comprises an upper solar energy transmission wall positioned above the upper extremity of the treatment chamber for enabling solar energy to be applied to the upwardly facing surface treatment zone. Water vapor evaporated from the treatment member is partially condensed on an inner surface of the upper solar energy transmission wall and collected at a lower location or locations in condensate collection unit. The treatment member is formed as the black or darkly opaque panel including an internal frame structure about which a flexible plastic film web/webs is wound. The panel has an upwardly facing curved ripple or wave surface and an upwardly facing concertina surface, which is formed by alternating ridges and valleys. The surface treatment zone has a lower water impervious surface and an overlying upper layer of web material, fabric material or netting material to allow water to flow to the water impervious surface. The treatment surface zone has an upwardly facing surface effect to promote water flow evenly across the surface zone. The outer flexible skin is partly transparent or translucent to form the upper solar energy transmission wall for allowing passage of solar energy to the water treatment member. The condenser unit is formed by a defined inner surface region or regions of the outer flexible skin, which is formed by an innermost plastic material film web wound onto the space frame with applied or retained tension. The inner surface of the upper solar energy transmission wall on which the water vapor condensed is formed by a continuous plastic material web absent of any intermediary joins. The plastic material film web or webs include self adherence and/or self sealing characteristics, and are pre-stretched to beyond its yield point to increase its length and decrease its thickness while retaining an ability to constrict onto the space frame. The outer flexible skin completely encloses the space frame. The condensate collection unit is formed as a channel or duct at a lower extremity of the defined inner surface region or regions of the outer flexible skin, where the channel or duct is useful to collect downwardly flowing condensate. The space frame includes a first pair of elongate frame members crossing one another in an X configuration, where outer ends of the first pair of elongate frame members is located at the corners of a square or rectangular shape. The outer ends of the first pair of elongate frame members have corner arms perpendicularly extending to the first pair of elongate frame members. A second pair of elongate frame members joins the corner arms on opposed sides of the space frame. A peripheral web of plastic material film is wound about the corner arms. The outer flexible skin is wound about the space frame including the peripheral web or webs of plastic material film. The space frame defines a substantially uniform rectangular cross-section along a longitudinal length dimension defining the treatment chamber, and an upper or front face of the outer flexible skin. The outer flexible skin defines a rear face, two opposed side faces, and two opposed end faces. Water from the supply unit flows onto an upper end of the panel and downwardly over the surface treatment zone formed on the panel. The panel is spaced from both the upper or front face and the rear face of the solar still module, and is positioned in a liquid impervious tray member, which is open in an upward direction. The upper or front face of the module forms an acute angle with a first end face of the space frame. The first end face of the space frame forms a lower end of the solar still module, where the space frame extends upwardly at an inclined angle from the first end face. The fan unit directs a flow of gas downwardly along an inner surface of the upper or front face of the module, and promotes vibration in the upper or front face of the outer skin. The water supply unit comprises a spray nozzle to spray water to be treated over the surface treatment zone, and a hose or pipe with outlet unit disposed along its length to release water to the surface treatment zone. The hose or pipe has porous sections to release water to the treatment zone. The heating unit is positioned within the flexible plastic film web or webs wound on the internal frame structure, is activated or deactivated to externally heat water to be treated flowing on the panel in response to variations in solar energy supplied to the module, and is operated by electrically supplied energy. INDEPENDENT CLAIMS are included for:    (1) a solar still arrangement;    (2) a panel member; and    (3) a water treatment panel.    DESCRIPTION OF DRAWING(S) - The diagram shows a solar still module.    Solar still module (10)    Space frame (12)    Outer flexible skin (43)    Film web (44)    Upwardly facing solar energy transmission wall. (46)