The composition of a water filter refers to the materials and components used to purify water effectively. Most high-quality filters are built with multiple layers, including a sediment filter to remove dirt and rust, activated carbon to eliminate chlorine and odors, and advanced elements like ceramic, ultrafiltration membranes, or reverse osmosis membranes to target microscopic contaminants. Some filters also include mineral or alkaline layers to enhance water quality and taste. The housing is typically made from durable, food-grade plastic or stainless steel to ensure long-lasting performance and safety. Each component plays a vital role in delivering clean, safe, and refreshing drinking water.