Quick Answer
Some municipalities add fluoride to drinking water to help prevent tooth decay, typically around 0.7 parts per million. It is a deliberate, regulated addition — not a filtration byproduct — and it is not what shower filters are designed to address.
Problem
Fluoride appears in water reports and sparking questions about what it is and whether filtration removes it.
Product Recommendation
ZOOSHEN is shower filtration; it does not target fluoride. For drinking-water questions, consult products and standards specific to drinking water. See /water-science/how-to-read-water-report to find your numbers.