Also, RO water has very low pH but if you just put a powerhead (PH) or a bubbler over the course of 24 hours you will see pH rise. Now add salt mix containing trace elements you will have an even increased pH from about 7.7-8.3. In this hobby consistancy is better than having high pH which is why I do nothing to raise my pH.
Make sure you have enough flow and you are turning your water over at least 15 times/hour, have a skimmer, and a powerhead agitating the surface making sure you have good gas exchange.