you dont use plain peat so all the info wont help here. peat, as you can see is way to low in pH, its why its only used as a base in soiless forumlas, then the other ingredients added to it in the bag are higher to ballance it out a bit, then they add a set amount of lime, depending on what the final ph is and this will buffer it to roughly 6.8 as new, thats what ph buffered means, some think it means no need to ph what we feed or water in it..thats not true. look up what buffer even means for those that still dont believe, the word alone means to slow or cushion in a way. not meaning its set ph. set would mean no need to ph. buffered means it wont go up n down as much as non limed soil mixes is all.
actualy heres what that means ......Chemistry A substance that minimizes change in the acidity of a solution when an acid or base is added to the solution.