A method (10, 10') for cyanobacteria removal in an aqueous solution, comprising the following main steps: - a first main step of determining a percentage of coagulable dissolved aromatic organic matter to remove corresponding to a cyanobacteria percentage concentration to remove; - a second main step of determining an optimal coagulant dose corresponding to the determined percentage of coagulable dissolved aromatic organic matter to remove and; - a third main step of applying said optimal coagulant dose as the adjusted coagulant dose for cyanobacteria removal; the method comprising, prior to the main steps (200, 210, 220), the following preliminary steps: - a first preliminary step of determining the cyanobacteria concentration percentage to remove; - a second preliminary step of measuring the turbidity of the aqueous solution; - a third preliminary step of measuring the dissolved aromatic organic matter of the aqueous solution; - a fourth preliminary step of identifying for the aqueous solution a category among at least two categories (171, 172) of water according to the measured turbidity and dissolved aromatic organic matter of the aqueous solution, each category of water being determined according to a couple of values of turbidity and dissolved aromatic organic matter, each category of water providing a relation between the percentage of cyanobacteria concentration to remove and the percentage of coagulable dissolved aromatic organic matter to remove; the first main step using said relation and the determined cyanobacteria concentration percentage to remove. - a first main step of determining a percentage of coagulable dissolved aromatic organic matter to remove corresponding to a cyanobacteria percentage concentration to remove; - a second main step of determining an optimal coagulant dose corresponding to the determined percentage of coagulable dissolved aromatic organic matter to remove and; - a third main step of applying said optimal coagulant dose as the adjusted coagulant dose for cyanobacteria removal; the method comprising, prior to the main steps (200, 210, 220), the following preliminary steps: - a first preliminary step of determining the cyanobacteria concentration percentage to remove; - a second preliminary step of measuring the turbidity of the aqueous solution; - a third preliminary step of measuring the dissolved aromatic organic matter of the aqueous solution; - a fourth preliminary step of identifying for the aqueous solution a category among at least two categories (171, 172) of water according to the measured turbidity and dissolved aromatic organic matter of the aqueous solution, each category of water being determined according to a couple of values of turbidity and dissolved aromatic organic matter, each category of water providing a relation between the percentage of cyanobacteria concentration to remove and the percentage of coagulable dissolved aromatic organic matter to remove; - a first preliminary step of determining the cyanobacteria concentration percentage to remove; - a second preliminary step of measuring the turbidity of the aqueous solution; - a third preliminary step of measuring the dissolved aromatic organic matter of the aqueous solution; - a fourth preliminary step of identifying for the aqueous solution a category among at least two categories (171, 172) of water according to the measured turbidity and dissolved aromatic organic matter of the aqueous solution, each category of water being determined according to a couple of values of turbidity and dissolved aromatic organic matter, each category of water providing a relation between the percentage of cyanobacteria concentration to remove and the percentage of coagulable dissolved aromatic organic matter to remove; the first main step using said relation and the determined cyanobacteria concentration percentage to remove.