AbstractpH, oxidation-reduction potential (ORP) and dissolved oxygen (DO) concentration are important parameters in water quality surveillance and treatment. The changes of these parameters are associated with electron density in water. Several techniques including electrolysis and catalysis which require redox reactions and electron exchange are employed to improve these parameters. In recent years, studies reported that magnetic effects can impart considerable changes on the pH, ORP and DO concentration of water. However, the correlation between electron density and magnetic effects on these parameters has yet to be disclosed despite the fact that increased electron density in water could improve water’s reductive properties, heat capacity and hydrogen bonding characteristics. In this study, the magnetic effects on pH, ORP and DO concentration were investigated using different magnets arrangements and water flow rates based on reversed electric motor principle. Results showed that the improvement of pH, ORP and DO concentration from 5.40–5.42 to 5.58–5.62 (+ 3.5%), 392 to 365 mV (− 6.9%), and 7.30 to 7.71 mg L− 1 (+ 5.6%), respectively were achieved using combined variables of non-reversed polarity magnet arrangement (1000–1500 G magnetic strength) and water flow rate of 0.1–0.5 mL s− 1. Such decrement in ORP value also corresponded to 8.0 × 1013 number of electron generation in water. Furthermore, Raman analysis revealed that magnetic effect could strengthen the intermolecular hydrogen bonding of water molecules and favor formation of smaller water clusters. The findings of this study could contribute to potential applications in aquaculture, water quality control and treatment of cancer attributed to free radical induced-oxidative stress.