Backwashing can be manual or automatic, on a set-time interval or at a specific pressure drop. This type of filter should be used as the first filter if the water source is a sand pumping well or a fast-moving stream. It should be followed by a media and screen filter for surface water sources, or screen or wafer filter for well water. Chemical Treatment Chemical treatment is often required to prevent emitter plugging due to microbial growth. The attachment of inorganic particles to microbial slime is a significant source of emitter plugging.
Chlorination is an effective measure against microbial activity.
Use chlorine and all other chemicals according to label directions. Chlorination is the most common method for treating bacterial slimes. Since bacteria can grow within filters, chlorine injection should occur prior to filtration. The higher concentrations axe often more economical. It is the easiest form of chlorine to handle and is most often used in drip-irrigation systems.