In BWTS, seawater needs to be pre-treated before entering the electrolysis or ultraviolet device. Pretreatment usually uses a high-flow automatic backflushing filter. It is used to remove phytoplankton and total suspended solids (TSS) of 50 μm and above in seawater and improve the NTU removal rate and the sterilization efficiency of electrolysis or ultraviolet units. This minimizes sediment retention in ballast tanks. For this reason, we have developed the HydroBwt® series auto backwash filter specially used for ballast water treatment. Two types of filter elements can be installed inside it, namely wedge wire candle filter and sintered metal filter.