There are three parts to a cartridge filter: end caps (typically made of plastic), a core structure to provide strength (often PVC), and a pleated media (often polyester) with a continuously graded, fixed pore structure.
[citation needed] When maintenance is efficiently performed, it can take only a few minutes to return a filtration system to operation.
[citation needed] The fossilised remains of diatoms are mined as diatomaceous earth, which is used to manufacture the white, unscented powder widely used in industrial filtration applications, and available for spa pool filtration cartridges.
[citation needed] Though are being marketed for centralized water treatment systems, most ceramic filters are now being manufactured for point-of-use applications.
The advantages of ceramic filters are their ease of use, long life (if not broken), and fairly low cost.
Disadvantages include possible recontamination of stored water since there is no chlorine residual and a relatively low flow rate - typically one to two litres per hour.
Maintenance means backwashing where the flow of clean water is reversed back into the filter.