Itโs a process that doesnโt guarantee good results, but that doesnโt mean you wonโt get them either. Itโs a risk because you donโt know exactly how many nutrients are still available in the soil and what you might need to add to balance it. Iโd only do it if the previous grow was organicโotherwise, I wouldnโt risk it.
That being said, my Durban Poison actually grew in reused soil, and I didnโt have major issues, just a slight excess of CalMag in the early stage, which forced me to do a flush-style watering to balance the nutrients in the soil.
To reuse my soil, I stored it in a plastic container for a month, watering once a week with molasses to let it cook over time. I added some fresh soil, a bit of SuperSoil, worm humus, mycorrhizae, and leftover solid nutrients from previous grows, like silica, fish meal, blood meal, alfalfa, and dolomite.
Thatโs also why I took the riskโit was more about using up the leftover nutrients I had at home and avoiding the hassle of carrying old soil from my room to the garden. ๐คฃ