The effectiveness of a number the test samples of new antiscalants (lightly crosslinked polymers of acrylic and methacrylic acids and crosslinking agents based on allyl ethers and other compounds, and a copolymer of maleic anhydride and methacrylic acid) has been experimentally compared with that of traditionally used scale inhibitors based on hydroxyethylidene diphosphonic acid, nitrilotriphosphonic acid, and the commercial inhibitor Aminat-K. The results of the experimental study of the kinetics of formation and buildup of the crystalline deposit of calcium carbonate in the presence and the absence of scale inhibitors depending on the composition of feedwater and the yield of a filtrate are reported. The experiments have been performed with the use of feedwater from the Moscow water-supply line. Equations for determining the rates of formation of calcium carbonate deposits in membrane devices in the presence of an inhibitor depending on the chemical composition of feedwater and the filtrate yield have been derived; these equations make it possible to recommend a work-cycle time before chemical cleaning operations.