The process of fulvic acid (FA) coagulation using aluminum coagulants (alum, polyaluminum chloride, and aluminum chloride) was studied in order to improve FA rehymoval during water treatment. The mechanism of FA removal is directly related to the form of aluminum in solution. Specific conditions and aluminum species that exist during the charge neutralization‐precipitation, adsorption, and simultaneous precipitation reaction mechanisms are discussed, as is the effect of calcium on FA removal.