A composition for controlling the deposition of scale imparting species on the structural surfaces of steam generating systems comprising the use of a water soluble polymer having the structure wherein R1 is H or lower (C1-C4) alkyl, R2 is (CH2-CH2-O)n, or a mixture of both, and n is an integer of from about 1 to about 40, R3 is H, lower (C1-C4) alkyl or an acetate. This polymer may also be used in concert with topping agents such as phosphoric acids, phosphonic acids, amines, metal chelating agents and oxygen scavengers.