SunSun CPA-10000 Bio Pressure Pond Filter UVC 11W up to 12000l koi Advantages: Mechanical and biological pressure filter with integrated UVC-clarifier. All connections and technology are in the lid/cover, the filter can be buried to lid for concealment without difficulty. Flush back function with maintenance indicator. The EasyClean flush back function: • Switch position "Filter" Normal operation - the water passes through the pressure pond filter with the help of a pond pump and returns cleanly into the pond. • Switch position "Clean" Cleaning mode - By turning the switch the motor that is integrated in the top of the filter is switched on and makes the filter sponges rotate in the inner of the pond filter and cleans them from the coarse dirt without opening the pond filter. During the cleaning operation the dirty water is drained by an additional connection and can be used for example for garden irrigation.