Comparative effectiveness studies were conducted using sodium carboxy-methylcellulose (Na-CMC) as an inhibitor of calcium sulfate scaling on membranes under different hydrodynamic conditions of dead-end ultrafiltration. It was shown that dead-end ultrafiltration conducted in the presence of 16 mg/L inhibitor with a periodic pressure release to zero ensures an enhanced capacity of membranes by a factor of 1.3 while the time of stable operation increases about 2-fold as compared with dead-end ultrafiltration under a constant pressure. In this case, the initial capacity of membranes can be fully recovered by washing with water.