Grohe Blue Carbon Filter, L-Size 40412GROHE Blue Filter for fresh, filtered water The GROHE Blue L size filter (capacity 2500 l at 20 dKH) turns ordinary tap water into a premium table water. Through five purification phases, the water is continually refined into a soft potable water with a wonderful taste. Undesirable substances, fine particles and heavy metals are filtered out and the lime content is reduced, leaving pure, great tasting water. The filter cartridge is easy to replace