The filters Plastica Alfa are used in ultra filtration systems as a necessary step for water pre-treatment to make the system more efficient. In particular, the batteries of Alfamatic self-cleaning filters, disk filters for the filtration of particles from 100 to 200 microns, thanks to their modularity and versatility are used for various purposes such as: treatment of process water, gray water, pre-filtration for drinking and desalination, filtration of water recirculation for irrigation, etc.