Multimedia filtration is typically used to remove particulate matter from waste water or as a form of pretreatment for process water. A multi-media filter typically consists of three different media layers, anthracite coal, sand and granite. Each layer serves to filter out particles of different sizes, with the larger particles filtered on the top layer and the smaller particles filtered on the bottom layer.

Multimedia filters are typically used as side stream filters for cooling tower systems exposed to environmental contamination. Contamination is often identified by sediment or sludge build-up in the basin and discolouration of system water.

Over time multimedia filters can be fouled with suspended solids, organic matter and debris. This kind of fouling deteriorates performance by reducing flow throughput and backwash efficiency. Hydro Flow conduct services, refurbishments and regenerations on media filters to improve the filter run time between backwashes and increase the efficiency of particulate removal.