A method of controlling the deposition of silica containing scales and their adhesion to surfaces in contact with an aqueous system is disclosed which comprises adding to the aqueous system about 1-500 ppm of a water-soluble or dispersible hydrophobically modified polyether polymer. Exemplary hydrophobically modified polyether polymers include alkylene oxide hydrophilic backbone repeat units and hydrophobic groups that may be attached to the backbone at a variety of locations such as 1) at the ends of the backbones, 2) either regularly or randomly spaced along the backbone length, or 3) as linking groups to link two or more portions of the backbone together.