Originally Posted by
Willie
My recommendation is to do nothing as the water parameters are ideal for discus. Your pH would drop, not rise, with fish waste, which the discus does not mind at all. When you see it drop, just make a water change. How much water to change depends very much on your set up. If you change more, then you can do so at longer frequency.
Crush coral will indeed increase hardness and reduce pH fluctuation, but that does not necessarily apply to your situation. African cichlid keepers routinely do this. Some even use crush coral in place of gravel. However, crush coral dissolves very slowly and hardness increases equally slowly. Of course, African keepers never change their water and are perfectly fine with their situation. That would not be true for discus.
Newcomers to this hobby always obssess over water conditions. In fact, hygiene - clean water - is far more important than the actual pH or KH. I've raised discus in 100% R/O (no additives) with weekly water changes and have had them do absolutely fine. Of course, I wouldn't recommend going much longer than a week...