A method for monitoring deposit formation in a process comprising an aqueous flow, said method comprising providing a feed flow of an aqueous liquid to be monitored onto a receiving surface, wherein the monitoring includes the steps of: - illuminating at least part of said receiving surface with at least one light source; - collecting with an imaging device (70,82) visual data at a multitude of positions across said receiving surface by moving the imaging device (70,82) at a multitude of positions across said receiving surface (72,80a-80c); - analyzing said visual data; - classifying the quality and the type of deposition (12,22,23,33,42,52) attached to said receiving surface based on a comparison of information obtained from said analyzed visual data to stored visual reference data; and - computing a quantitative scaling and/or fouling indication of said receiving surface based on said classification; wherein distribution and control of the incoming feed flow is performed by the receiving surface which is a membrane (10,20,30,40,50) and a mesh-like network (11,21,31,41,51) that is placed on the top of the membrane (10,20,30,40,50), wherein the classification of the quality and the type of said depositions on said receiving surface is done in a computer by comparing the obtained visual data to the stored visual reference data of one or more factors selected from shape factors such as aspect ratio, size factors such as size distribution or mean size, color factors such as mean color, color distribution and brightness, of the depositions imaged, and wherein the quantitative scaling and/or fouling indication is used as an input parameter for automatic control of the addition of one or more chemicals to said feed flow. - illuminating at least part of said receiving surface with at least one light source; - collecting with an imaging device (70,82) visual data at a multitude of positions across said receiving surface by moving the imaging device (70,82) at a multitude of positions across said receiving surface (72,80a-80c); - analyzing said visual data; - classifying the quality and the type of deposition (12,22,23,33,42,52) attached to said receiving surface based on a comparison of information obtained from said analyzed visual data to stored visual reference data; and - computing a quantitative scaling and/or fouling indication of said receiving surface based on said classification; wherein distribution and control of the incoming feed flow is performed by the receiving surface which is a membrane (10,20,30,40,50) and a mesh-like network (11,21,31,41,51) that is placed on the top of the membrane (10,20,30,40,50), wherein the classification of the quality and the type of said depositions on said receiving surface is done in a computer by comparing the obtained visual data to the stored visual reference data of one or more factors selected from shape factors such as aspect ratio, size factors such as size distribution or mean size, color factors such as mean color, color distribution and brightness, of the depositions imaged, and wherein the quantitative scaling and/or fouling indication is used as an input parameter for automatic control of the addition of one or more chemicals to said feed flow. wherein distribution and control of the incoming feed flow is performed by the receiving surface which is a membrane (10,20,30,40,50) and a mesh-like network (11,21,31,41,51) that is placed on the top of the membrane (10,20,30,40,50), wherein the classification of the quality and the type of said depositions on said receiving surface is done in a computer by comparing the obtained visual data to the stored visual reference data of one or more factors selected from shape factors such as aspect ratio, size factors such as size distribution or mean size, color factors such as mean color, color distribution and brightness, of the depositions imaged, and wherein the quantitative scaling and/or fouling indication is used as an input parameter for automatic control of the addition of one or more chemicals to said feed flow.