Horizontal sand filters are made of polyester reinforced with fiberglass; they are totally anti-corrosive, and have high mechanical, chemical and thermal resistance, Higher quality water is achieved with their greater filtering capacity. Indexes of turbidity and contaminants of the filtered water are reduced due to their increased retention capacity. The time between back washes increases proportionally with the height of the filter bed, meaning there are fewer interruptions in filtration, and lower water consumption, because the number of back washed needs is decreased and there is less erosion of the filtering material.
A horizontal filter is the ideal choice in cases where a great volume of water is to be treated, and in cases which require optimization of the available space, as a single horizontal filter can substitute up to 3 vertical filters of the same diameter simply by increasing its length.