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 , filter foams and biospheres in the bottom chamber. * If your model was made pre-2015 you need an official single-ended Laguna 20w bulb, however a regular single-ended18w bulb is sufficient with any models made 2015 onwards. NOTE: UVC bulb included.