Fluoride removal from lake water

I am from Rwanda and we use lake water for drinking and other purposes. This lake water has high fluoride concentrations.  As an environmental scientist, I am thinking of adopting a sustainable solution that would eliminate the negative health effects caused by high amounts of fluoride in the water. One of the adverse health effects I observed is the black teeth of residents here.  I am thinking of making a household filter that can be used to  reduce the  fluoride concentration. What methods could be used to reduce the fluoride concentration in households? Is there a practical household filter available on the market?