For some years I have been dumping used mediums of peat, coco and in the early days FFOF into one corner of the back yard. Last summer I threw some tomatoes over it and had my farmer neighbors jealous as could be. Being in a perpetual financial challenge I almost always use it twice. Never added lime when reblending. More like just a good drying pulling root fiber balls, and adding worm castings. Now though I think like Otter says we can try adding the buffering agent as well. Plus I don't think Otter wants me throwing those root fibers away either.Do you have another garden you could reuse your peat in? I just add mine to the outdoor beds. Although I haven't tried it, you could probably also give the peat a good flushing and then recharge it with a new addition of Lime. Somewhere in my travels I read the Lime addition in most soil-less mixes last about 4-5 months of growing. So I'd do 100% of the original mix since it's probably about spent by the time we harvest anyhow. I tried coco one run and it wasn't for me. Increased watering and it doesn't buffer like peat mixes, so you have to to worry about pH. Didn't see any better yield so I didn't see the point of the extra fuss.
The song from Pink Floyd is still so spot on it is ridiculous.