Water Treatment Specialists Multi-Media Filters consist of several types of media and gravel under bedding. Multi media filtration is used to remove suspended solids from water and wastewater. Water Treatment Specialists manufactures skid-mounted or stand alone system that are factory assembled, wired, tested, and delivered ready for installation. Multi-media filtration is a proven design; the coarse media layers in the top of the tank trap large particles, and smaller particles are trapped in the finer layers of media deeper in the bed. The result is highly efficient filtering since removal takes place throughout the entire bed. This type of sediment filtration is ideal for a pre-treatment process to any reverse osmosis system helping to ensure long life of the membrane elements.