You should start slowly. Set the controls to the lowest level and drink one to three glasses per day. Assuming the water agrees with you, increase the amount you drink and the level of ionization intensity. High levels of alkalinity -- up to 9.5-10.0 -- are best for drinking water; the highest levels can be used for cooking. In a few individuals, the detoxification effects from drinking alkaline ionized water can cause headaches and diarrhea for a short time. And for some older people, ionized water can tend, at first, to open the bowels. This is why a slow start is advised. Use the “Purified Water” setting for taking any medications that your doctor advises not to be taken with alkaline water. Do not drink the acid water. Having said all of the above, be aware that millions of Japanese have been drinking alkaline ionized water daily over the last 30 years. The water ionizer has been approved as a Household Medical Instrument by the government of Japan. In addition, test results on safety by the Welfare Ministry in Japan reveal no harmful influences on the body.