The method by which fluoride is added to water supplies depends on several factors.
Most smaller systems add fluoride in solution.
Solutions are manually prepared in large day tanks. Tanks may be elevated to provide gravity feed or may be connected to pumps to provide mechanical feed. Either way, water flow past the point of addition is monitored to prevent the possibility of exceeding the MCL limits. Fluoride must be added to the water supply upon completion of all treatment steps. Chemicals containing calcium that are used to treat the raw water, will cause the fluoride ion to coagulate along with other impurities.