I have never thought pH was an issue with discus, with the exception of breeding, and with tank bred discus, even that is not an issue unless you have an unusually high pH. When I started doing discus, it was in Omaha, Nebraska, where we had hard water and a pH in the high 7s. But the fish were local bred, and already acclimated to those conditions. I think what's more important is to make sure you have good water conditions and a temperature in the mid-80s. Good water conditions means good filtration and frequent water changes. In my humble opinion, a python connected to a laundry sink was always mandatory equipment. My biggest concern with discus was always internal parasites, so make sure you have some metranidazole-based medication handy.