Filtration of irrigation water involves removing organic and inorganic particulate matter (debris, sediment, soil particles, algae, etc.) from the water prior to treatment for pathogens. Pre-filtration is important for two reasons. Firstly, larger particulate matter has the potential to clog the irrigation system (e.g. emitters). Secondly, the effectiveness of many pathogen treatments (e.g. all chemical treatments using oxidizers, UV) is decreased significantly in the presence of particulate organic matter. You can learn more at the University of Guelph website.
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