5 Stages of second filter. 1. Granular Quality Carbon Layer: Reduces chlorine taste and odors, fast absorbing, generates low dust. 2. Pi-Ceramic Negative Ion Layer: Generates negative ion, making water clusters smaller. 3. BioMass Ball-Ceramic Layer: High quality ceramic filter designed for bacteria control. 4. Vitamin C Ceramic Technology™: Reduces Chlorine and Chloramines 5. Special Quality Sediment Layer: Prevents sediment discharge.