The difference between a 15-stage filter showerhead and a 20-stage filter showerhead lies in the number of filtration stages they offer. A stage refers to a specific layer or process of filtration that the water goes through.

Both showerheads are designed to remove impurities, such as chlorine, heavy metals, sediment, and other contaminants from the water. The additional stages in a 20-stage filter showerhead typically offer extra layers of filtration, which may include additional materials or technologies aimed at providing a more thorough purification process.

While a 15-stage filter showerhead can effectively improve water quality, a 20-stage filter showerhead may offer an even higher level of filtration by targeting a wider range of pollutants. The specific features of each stage can vary between different models and brands, so it's important to check the details provided by the manufacturer to understand the specific benefits and technology behind each type of filter showerhead.

Ultimately, the choice between a 15-stage and 20-stage filter showerhead depends on your personal preferences, the water quality in your area, and your desire for a more comprehensive filtration experience.