. My RO water is around 8.0 so I still need to
buffer it to the pH that I want. The KH (carbonate hardness) also goes down
when using RO water. KH is a measure of the buffering capacity of the
water. So with a lower KH (buffering capacity) the RO water may have a
lower pH than your tap water, but it may not be lower. Because of the lower
KH you have to be careful when adding buffer to RO water, it doesn't take
much to change the pH!