I thought I had seen a thread recently on RO water PH, and now I can't seem to find it. I recently purchased an Express Water RO system with UV and DeIonizer. I havent used the water for brewing yet, but am getting ready to. I have check the PH of the RO water and it is near 9.5. Everything I have read says RO water should have a PH of ~7. Is it normal to have a water PH of 9.5 for RO? I have also tested in input water and the PH is near 10. I even re-calibrated by PH meter to be sure the measurement was right.