The most common filter used for drip irrigation systems is the disc filter or ring filter. Disc filters are composed of a series of stacked rings or discs that, when compressed, form a filtering mesh. Filtration takes place as the water flows through the grooves formed by the rings, retaining the solid particles on their surface. Disc filters are available in different filtration grades, ranging from 20 to 200 microns. For irrigation, 130 micron filtration is typically used.

Disc filters are effective at removing a wide range of solid particles, including sand, silt, algae, and other debris. They are also relatively inexpensive and easy to maintain. However, they can be plugged by organic matter, such as leaves and grass clippings, so it is important to keep the irrigation system clean.

Other types of filters that can be used for drip irrigation systems include:

• Screen filters: Screen filters are the simplest and least expensive type of filter. They consist of a mesh screen that traps solid particles as the water flows through it. Screen filters are effective at removing large particles, such as sand and gravel, but they are not as effective at removing smaller particles, such as silt and algae.
• Media filters: Media filters use a granular material, such as sand or gravel, to trap solid particles. Media filters are more effective than screen filters at removing small particles, but they are also more expensive and require more maintenance.
• Centrifugal filters: Centrifugal filters use centrifugal force to separate solid particles from the water. Centrifugal filters are very effective at removing large particles, but they are also more expensive and require more maintenance than other types of filters.

The type of filter that is best for a particular drip irrigation system will depend on the quality of the water source and the desired level of filtration. If the water source is high in sediment or other debris, then a disc filter or media filter is recommended. If the water source is relatively clean, then a screen filter may be sufficient.