You don't have enough information to move forward. For example, my water straight out of the tap is pH 8.8. After 24 hours of conditioning, just an airstone and a heater, the pH drops to 7.5. Also, you don't know the hardness. My tap water is only 125 ppm TDS, so high pH does not equate high levels of hardness.
My suggestion is follows. Take a sample of straight tap water, a sample of water out of the R/O, with or without conditioning, and ask the local fish store to run both pH and TDS. Once you have actual data, then what to do becomes very straight forward.