Stop, before you go any further with altering your water.....unless it is absurdly high pH 8.2+++ I wouldnt mess with it. Discus can and will great in just about any water so long as it is clean and warm (82+). I and many others keep discus in straight tap water. Some are even having success with a pH of 8.5 and liquid rock for water. Dont worry about the water parameters so much. Just make sure the water is warm, and that you do frequent water changes. All else will be good.
-Ryan