The filter and check valve should be replaced every six months. The Cartridge Filter converts activated oxygen back to regular oxygen as it leaves the SoClean 2 chamber. The check valve prevents water from your CPAP from possible damage to CPAP electronics.
SoClean has discovered counterfeit Cartridge Filter Kits being sold, particularly on Amazon® and eBay®, with check valves and filters, that leak and can cause damage to your SoClean machine or to your property due to water leakage from the counterfeit check valves. Please purchase your Cartridge Filter Kits from SoClean® only.