Sand / Hydro-Anthracite Filters
Hydro anthracite is a selected, hard and clean coal of a pure natural origin. It is used in closed filter systems for purification of drinking water, process water, pool and waste water. This filter medium is usually combined with different sizes of filter sand in a multibedfilter. The largest grains are covering the lower distribution system in the filter tank. The hydro anthracite forms the top layer and improves the fineness of the filter.
Filter Sand (gravel) is used in closed backwash filtration systems. It’s available in different grain sizes and is generally used as multibed-filter material for an optimal division and appropriate filtration speed. The rudest fraction is always situated underneath the system and covers the distribution system from the filter tank. This supporting layer is used for al the other filter media.