Apparatus for treating water at low cost for use as raw material in at least one downstream industrial process, which eliminates suspended solids in the water by filtering a small fraction of the total volume of water, the apparatus comprising: - at least one feeding line of water to at least one containing means; - at least one containing means, wherein the containing means has a volume of at least 15,000 m 3, which comprises a receiving means for settled particles, and wherein the receiving means is affixed to the bottom of the containing means and is constructed of a non-porous material capable of being cleaned, so that the bottom of the containing means is covered with the non-porous material allowing the mobile suction means to travel across the entire inferior surface of the containing means and suction the settled particles; - at least one coordination means, where the coordination means comprises electronic devices which is configured to receive information regarding water quality parameters, processing that information and activating chemical application means and mobile suction means to adjust parameters of the water within limits specified by the coordination means; - at least one chemical application means, which is activated by said at least one coordination means; - at least one mobile suction means, which moves through the bottom of said at least one containing means suctioning the water flow containing the settled particles; - at least one propelling means that provides movement to said at least one mobile suction means so it can move through the bottom of said at least one containing means; - at least one filtration means that filters the water flow containing the settled particles; - at least one collecting line coupled between said at least one mobile suction means and said at least one filtration means; - at least one return line from said at least one filtration means to said at least one containing means; and - at least one water outlet line from said at least one containing means to the at least one downstream industrial process; wherein the coordination means is configured to vary the flow of treated water to the downstream industrial process based on information such as output or production rate. - at least one feeding line of water to at least one containing means; - at least one containing means, wherein the containing means has a volume of at least 15,000 m 3, which comprises a receiving means for settled particles, and wherein the receiving means is affixed to the bottom of the containing means and is constructed of a non-porous material capable of being cleaned, so that the bottom of the containing means is covered with the non-porous material allowing the mobile suction means to travel across the entire inferior surface of the containing means and suction the settled particles; - at least one coordination means, where the coordination means comprises electronic devices which is configured to receive information regarding water quality parameters, processing that information and activating chemical application means and mobile suction means to adjust parameters of the water within limits specified by the coordination means; - at least one chemical application means, which is activated by said at least one coordination means; - at least one mobile suction means, which moves through the bottom of said at least one containing means suctioning the water flow containing the settled particles; - at least one propelling means that provides movement to said at least one mobile suction means so it can move through the bottom of said at least one containing means; - at least one filtration means that filters the water flow containing the settled particles; - at least one collecting line coupled between said at least one mobile suction means and said at least one filtration means; - at least one return line from said at least one filtration means to said at least one containing means; and - at least one water outlet line from said at least one containing means to the at least one downstream industrial process;