Why is purification of water and nutrient salts so important in studies involving mineral nutrition using hydroponics?

(N/A) Hydroponics is the technique of growing plants in a nutrient solution in the absence of soil.
Since the plant roots are exposed to a limited volume of the solution,any impurities in the water or nutrient salts can lead to toxicity or nutrient imbalance.
Furthermore,to ensure that only the specific minerals being studied are affecting the plant's growth,it is essential to use highly purified water and nutrient salts.
This prevents contamination and ensures that the observed physiological responses are solely due to the experimental variables,thereby maintaining optimum plant growth.