Whirlpool filters consist of a special fleece which was created to absorb a lot of grease and dirt. To remove the grease and dirt from the fleece you need a special filter cleaner.
Lotus Clean Filter Wash Natural was developed especially for cleaning fleece filters.
Conventional non-woven filters are made of cylindrical fibres (right picture). In contrast, Reemay® nonwoven filter material (pictured left) is shaped to allow as much dirt as possible to settle, but without restricting the water flow. Because of their shape, normal non-woven filters clog much more quickly and water can hardly flow through them.