Plants with the capability of accumulating heavy metals above concentrations that would typically cause harm or toxicity in plants are known as hyperaccumulators. Cannabis is a well-known hyperaccumulator with the ability to remove heavy metals contaminants from soils. This characteristic is desirable for soil remediation but troublesome when cannabis is grown for consumption.
If the nutrients you use are contaminated with heavy metals, your buds will be accumulating these heavy metals, exposing those who consume them.
Outsourced analysis of heavy metal concentrations:
For more information:
Plant-Prod