Solenco CF8608 Air Purifier PrefilterDetailed Description How long do the filters last? The filters of the Solenco CF8608 units last about 6 months application and environment dependent. However, not all need to be replaced at the same time. The Prefilter for example can last up to 2 years. When must I replace the filters on my Solenco CF8608? HEPA filter and Activated Carbon filter change: After operating 4 320 hours (6 months), the REPLACE FILTER light will turn on (blue) indicating