Our recommendation of water filters is based on public information shared by your water district and is only a suggestion. If your water source is from a source other than that stated in the recommendation or from a private well we would advise you have your water tested by a qualified water testing service. ** If you have specific health issues requiring your water to be free of specific contaminants we recommend that you consult your physician. Our customer service team would be more than happy to provide you documents on filter performance that you can review with your physician. For assistance please call us at 866-709-2086 Monday - Friday 9 am – 5pm EST.