Potable water was exposed to permanent magnetic field (PMF) with a magnetic flux density (B=1.45 T ± 0.05) to investigate its effect on some water parameters for different time intervals at open and closed flow conditions at flow rate of 41.93 L/min and 52.16 L/min , respectively. Such as these parameters are; electrical conductivity (EC), total dissolved solids (TDS), pH and temperature. In the existence of this permanent magnetic field, so these pervious parameters were also studied as a function of water flow rate in case of the open loop system. The results showed that the PMF fluctuates the tested parameters of the outflow of this potable water at the previous flow conditions. These effects are owing to the hydrogen bond network. Theoretical approach of calculating inter-molecular interaction energy of H-bonded systems of water clusters under the effect of magnetic field is performed using DFT (Density Functional Theory) level with B3LYP function on Gaussian 09 Program.