I don't do anything to my Ph, my Ph stayed at 8 too when I had eco-complete substrate. Now I have pool filter sand which is better for Discus. Most people recommend bare bottom but if using substrate Pool Filter Sand is best. My ph was usually around 7.5 once I started using it. Also Disacus need lots of water changes. I have learned it is best to let your water sit out for 24 hours with an air stone in it then take the ph, that is your true ph of your tap water. Most Discus keepers recommend aging your water in barrels.
