I looked to see if a topic existed on this already, but could not find one through the search function. I am interested to know what uses people have come up with for their used rockwool. Any rockwool that is in decent enough shape I will usually dry out again, remove the dried roots, and reuse until it is no longer good enough to use anymore. But at that point, I am not sure what to do with the stuff other than just throw it away. Someone who managed this system before me was just adding it into our compost (despite the fact that it clearly is not compostable), but I can say from experience that it just clogs up the garden beds... I still am pulling that stuff out of the gardens months later.
I have heard from somewhere that some people will use a shredder to finely shred it and then mix into compost or potting soil and I could see that being more practical but do not have a shredder yet to give it a try. Has anyone tried that? Any other uses out there others have tried (successfully or unsuccessfully)?