Never use products. They're temporary and often cause pH shock to fish. If you still have low pH, add some calcium like cuttlebone (pet shops selling bird supplies will have some) or liquid calcium to the water to bring the pH up. What kind of water are you using btw? Tap usually is much harder and needs to come down so I'm guessing either bottled or filtered water of some type? If not, then you're lucky. Most Discus keepers would practically kill for that kind of pH water.