Different results can be achieved when current passes through water. Normal water (tap water) would conduct electricity. However, it is not chemically broken down because it contains impurities such as many ions and minerals. Water that is clean of all impurities and in its purest form will conduct no electricity and it will remain chemically and physically unchanged. Electrolysis is the next possibility. This is only possible if you can pass DC current and, most importantly, acidify the water using dil. H2SO4 . You can use Hoffman voltameters to conduct electrolysis after passing the current water has been passed through both positive and negative electrodes.