Recycle and reuse.

Waste not want not. My soil mix is the most expensive aspect of my grows. I rejuvenate 1/3rd for next cannabis grow and the rest goes to top dress lawn and into garden. When I used synthetic nutrients, all went onto the lawn or into the garden.

Cool, thanks for the replies.

I also use syntetic nutes, with a bit of organics to feed the bennies....and i recycle all the soil....now im at the 6th run if im not wrong...no issues.
i think that if you keep yourself on the light side without overfeeding (i keep them on 600-700 ppm) thers no reason to not reuse it.
Most is marketing...and is also true that nute company reccomend crazy dosages...
I felt also that a big time enemy of the recycling soil are the godddamn PK boosters...absolutely unecessary and can cause lockouts because of the injustificable amount of Potassium and Phosphorus....