Probably the most simple, yet still effective, ways to magnetize water is to get what is called a water wand, a cylindrical magnet resembling a pen. This needs to be at least 2,300 gauss/230 m tesla. Then fill a pitcher with water and drop the wand in it. For two liters of water ( a little over 2 quarts) leave the magnet for one hour. However longer will not hurt.