I Only use , what plant doesn't use . Alot minerals are still thier. And I got fresh dirt.I just don’t use reconstituted 4 times Foxfarm soil…. I make fresh soil and they like it. you might want to try it. I know you add synthetics to it during the grow which of course is why your plants will grow in it at all but I just don’t see a good future in using old fox Farms soil for any reason. I’ll admit on the front end it’ll cost you a penny or two to get everything to make a batch but the way you grow it would last forever so ultimately it would be cheaper than using Fox Farms and your synthetic nutes Plus your harvest will be much better so anyway you look at it it’s a better deal….. just my opinion not that you ask….
I add bags all the time..