Filter aids are low-density, fibrous, or fine granular materials such as diatomite earth, cellulose, or inorganic mineral powders added to a solution to enhance the rate and quality of filtration. A filter aid can work in two different ways, as a pre-coat prior to the filtration of the slurry, or as a body feed to the liquid before filtration. The use of filter aid technology is ubiquitous in many industries, such as food processing, beverage, pharmaceuticals, chemicals, waste treatment, water treatment, and mining. Filter aid products come in different grades that allow a wide permeability range. The four main factors to consider when selecting the appropriate grade include the filtrate clarity, product throughput, product yield, and the product stability and purity. Filter aid products work in conjunction with a wide variety of filtration equipment; for example, chamber and filter press filters, belt press filters, leaf filters, tubular filters, rotary vacuum filters, and cassette depth filters.