When troubleshooting crop problems, think beyond nutritional toxicities or deficiencies.
Mechanical damage and unfavorable irrigation practices can result in symptoms that mimic nutritional problems.
For example, plants situated too close to a fan can suffer wind damage that results in chapped leaves. Or, if a grower neglects to irrigate a crop on time, a complete dry down of a plant's substrate can result in root death, which in turn results in cell death in the leaf.
The resulting damage in both of these examples closely resembles nutrient deficiencies in cannabis.
In this case, applying additional nutrients will not solve the issue, and in fact, may aggravate it.
Don't jump to a nutrition-related conclusion when your plant's leaves start to look funny. Use tests, production records, and creativity to sniff out the real culprit.