Just use the peat if you want too...avoid the water softner as it adds a lot of salt into the water...and the salt that is added has resins in it because the salt is in either pellet or block form. What is your pH once it has agedd (aerated) for 24 hours?? Most of the time, you dont need things like peat to change the water chemisty...discus can thrive in a pH from 5.0 up to 8.2 with ease. Hardness doesnt matter either.
-Ryan