Suitable for ponds with fish up to 16,000 litres.This pressure filter can be cleaned without opening the lid! Simply switch to \'waste\' mode and scrub the dirty filter sponges via the external handles - the dirty water exits the special waste outlet (see attached pictures). Also features a high powered 20w UVC x 2 (40w total) , filter foams and biospheres in the bottom chamber Please note this 20,000 set consists of two Pressure-Flo 10,000 filters supplied together with a sturdy T-piece and connecting hose for connection to a single pump. * If your model was made pre-2015 you need 2 x official single-ended Laguna 20w bulbs, however 2 x regular single-ended 18w bulbs are sufficient with any models made in 2015 or since. NOTE: UVC bulbs included.