he V2 Pure 5 Micron Cartridge Filter is a Sediment, Dirt and Rust remover. It is a Polypropylene filter is so fine it removes Sand, Silt, Dirt and Rust particles out of your aquarium to give you that crystal clear finishing look. For optimum results use this filter in temperatures below 65 degrees. The material used to make the prefilter meets F.D.A. specification and is carefully constructed to avoid potential contaminants.