The main purpose of this study was to investigate the effects of a magnetic treatment on the scaling power of hard waters using a non-electrochemical scaling method. The influence of this treatment on the calcium carbonate precipitation was confirmed. Experimental results showed that the scaling potentiality of the treated water was significantly inhibited by the applied magnetic field. The anti-scaling efficiency of the applied permanent magnets was about 45%. The rapid controlled precipitation (RCP) tests confirmed that the magnetic field produces a "memory effect". The anti-scaling properties of the treated water were retained for approximately three days following the magnetic treatment. (C) 2016 Elsevier B.V. All rights reserved.