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 11w UVC, filter foams and biospheres in the bottom chamber. * If your model was made pre-2015 you need an official single-ended Laguna 11w bulb, however a regular single-ended 11w bulb is sufficient with any models made 2015 onwards.