The Alkaline filter changes the acidic RO water into a perfect Alkaline Ionized Water. The PurePro® Alkaline filter simply gives back minerals such as ionized calcium, magnesium, sodium, potassium ion, which were taken away while purifying the water. Produces alkaline water which helps your body maintain a healthy pH level. The PurePro® Alkaline filter is effective and give the water pH value of 8.00~9.5