Abstract: A method for collecting matter using a matter collection Unit, as described below, provides a low energy, low cost and nearly zero pollutant process for extracting suspended and/or dissolved matter in a medium. The method collects the matter on a material when the medium is permitted to flow past the material which is disposed within a chamber, and the medium, with less suspended matter, can flow back to a medium body to permit, e.g., further growth and/or higher collection efficiency. The process can operate continuously alongside, e.g. a growth system, to harvest suspended matter until the matter is ready for extraction. Post extraction collected matter, e.g., can be converted into valuable commercial products or the process can be used to remediate a medium, such that the valuable product is a substantially cleaner medium.