Unfortunately, this is not true for all growers, just most. Would love it if cannabis only used the holy grail of organics to uptake nutes (passive ionic uptake). Unfortunately, cannabis is a hyper/dynamic accumulator. I firmly believe (until proven otherwise by labs) hydroponics is the only way to strictly control what cannabis is exposed to during flower. Everyone who's sampled my best runs call me a liar when I tell them it's hydro. People just assume it's the best damned organic cannabis they've ever had.You can argue til you're blue in the face, I am right the only truly clean product generally comes from organic gardens.
Might want to stop and do some research on it, you may eventually grow better cannabis.