Water travels through 6 stages of filtration:

6 Stage Stainless Steel Whole House Fluoride Water Filter

Cystal Quest Whole House Fluoride water filters are engineered for maximum filtration and maximum performance with minimum maintenance. They deliver trouble free operation for many years. It is the most advanced and effective Fluoride water filters in the market
First stage, water flows through a 20" sediment filter cartridge that removes sediment, silt, sand and dirt. Also extends the life of water softeners and water filters, and prevents damage to control valves or pumps.