Set of replacement Carbon & Claryum filter cartridges for the AQ-RO-3 Optim H2O Reverse Osmosis Drinking Water System. Carbon & Claryum filters (stage 1 & 3) should be replaced every 6 months or 365 gallons for optimal filter effectiveness. The Aquasana Optim H2O Reverse Osmosis Drinking Water System delivers the best drinking water available for optimal hydration. Optim H2O is the first reverse osmosis system of its kind to pair the powerful filtration of reverse osmosis with high performance Claryum filtration, plus remineralization. Remove the most contaminants from your water, like fluoride, lead, arsenic, asbestos, chlorine and chloramines, while maintaining the benefits of healthy minerals other reverse osmosis systems simply remove. NSF Certified to remove over 95% of fluoride, over 97% of arsenic, chlorine and chloramines, and over 99% of lead, asbestos, and more. A one year remineralizer is included with every system to provide healthy amounts of calcium, magnesium and potassium for optimally alkaline, p H balanced drinking water.